Well, the Toronto statement is from 1950. Here is the section about assumptions. As far as I can tell these are quite irreconcilable with Orthodoxy:
IV. THE ASSUMPTIONS UNDERLYING THE WORLD COUNCIL OF CHURCHES
We must now try to define the positive assumptions which underlie the World Council of Churches and the ecclesiological implications of membership in it.
1) The member Churches of the Council believe that conversation, cooperation, and common witness of the Churches must be based on the common recognition that Christ is the Divine Head of the Body.
The Basis of the World Council is the acknowledgment of the central fact that "other foundation can no man lay than that is laid, even Jesus Christ." It is the expression of the conviction that the Lord of the Church is God-among us Who continues to gather His children and to build His Church Himself. Therefore, no relationship between the Churches can have any substance or promise unless it starts with the common submission of the Churches to the Headship of Jesus Christ in His Church. From different points of view Churches ask "How can men with opposite convictions belong to one and the same federation of the faithful?" A clear answer to that question was given by the Orthodox delegates in Edinburgh 1937 when they said: "In spite of all our differences, our common Master and Lord is one—Jesus Christ who will lead us to a more and more close collaboration for the edifying of the Body of Christ." [From statement by Archb. Germanos on behalf of the Orthodox delegates.] The fact of Christ's Headship over His people compels all those who acknowledge Him to enter into real and close relationships with each other—even though they differ in many important points.
2) The member Churches of the World Council believe on the basis of the New Testament that the Church of Christ is one.
The ecumenical movement owes its existence to the fact that this article of the faith has again come home to men and women in many Churches with an inescapable force. As they face the discrepancy between the truth that there is and can be only one Church of Christ, and the fact that there exist so many Churches which claim to be Churches of Christ but are not in living unity with each other, they feel a holy dissatisfaction with the present situation. The Churches realize that it is a matter of simple Christian duty for each Church to do its utmost for the manifestation of the Church in its oneness, and to work and pray that Christ's purpose for His Church should be fulfilled.
3) The member Churches recognize that the membership of the Church of Christ is more inclusive than the membership of their own Church body. They seek, therefore, to enter into living contact with those outside their own ranks who confess the Lordship of Christ.
All the Christian Churches, including the Church of Rome, hold that there is no complete identity between the membership of the Church Universal and the membership of their own Church. They recognize that there are Church members extra muros, that these belong aliquo modo to the Church, or even that there is an ecclesia extra ecclesiam. This recognition finds expression in the fact that with very few exceptions the Christian Churches accept the baptism administered by other Churches as valid.
But the question arises what consequences are to be drawn from this teaching. Most often in Church history the Churches have only drawn the negative consequence that they should have no dealings with those outside their membership. The underlying assumption of the ecumenical movement is that each Church has a positive task to fulfill in this realm. That task is to seek fellowship with all those who, while not members of the same visible body, belong together as members of the mystical body. And the ecumenical movement is the place where this search and discovery take place.
4) The member Churches of the World Council consider the relationship of other Churches to the Holy Catholic Church which the Creeds profess as a subject for mutual consideration. Nevertheless, membership does not imply that each Church must regard the other member Churches as Churches in the true and full sense of the word.
There is a place in the World Council both for those Churches which recognize other Churches as Churches in the full and true sense, and for those who do not. But these divided Churches, even if they cannot yet accept each other as true and pure Churches, believe that they should not remain in isolation from each other, and consequently they have associated themselves in the World Council of Churches.
They know that differences of faith and order exist, but they recognize one another as serving the One Lord, and they wish to explore their differences in mutual respect, trusting that they may thus be led by the Holy Spirit to manifest their unity in Christ.
5) The member Churches of the World Council recognize in other Churches elements of the true Church. They consider that this mutual recognition obliges them to enter into a serious conversation with each other in the hope that these elements of truth will lead to the recognition of the full truth and to unity based on the full truth.
It is generally taught in the different Churches that other Churches have certain elements of the true Church, in some traditions called vestigia ecclesiae. Such elements are the preaching of the Word, the teaching of the Holy Scriptures, and the administration of the sacraments. These elements are more than pale shadows of the life of the true Church. They are a fact of real promise and provide an opportunity to strive by frank and brotherly intercourse for the realization of a fuller unity. Moreover, Christians of all ecclesiological views throughout the world, by the preaching of the Gospel, brought men and women to salvation by Christ, to newness of life in Him, and into Christian fellowship with one another.
The ecumenical movement is based upon the conviction that these "traces" are to be followed. The Churches should not despise them as mere elements of truth but rejoice in them as hopeful signs pointing toward real unity. For what are these elements? Not dead remnants of the past but powerful means by which God works. Questions may and must be raised about the validity and purity of teaching and sacramental life, but there can be no question that such dynamic elements of Church life justify the hope that the Churches which maintain them will be led into fuller truth. It is through the ecumenical conversation that this recognition of truth is facilitated.
6) The member Churches of the Council are willing to consult together in seeking to learn of the Lord Jesus Christ what witness He would have them to bear to the world in His Name.
Since the very raison d'tre of the Church is to witness to Christ, Churches cannot meet together without seeking from their common Lord a common witness before the world. This will not always be possible. But when it proves possible thus to speak or act together, the Churches can gratefully accept it as God's gracious gift that in spite of their disunity He has enabled them to render one and the same witness and that they may thus manifest something of the unity, the purpose of which is precisely "that the world may believe," and that they may "testify that the Father has sent the Son to be the Saviour of the world."
7) A further practical implication of common membership in the World Council is that the member Churches should recognize their solidarity with each other, render assistance to each other in case of need, and refrain from such actions as are incompatible with brotherly relationships.
Within the Council the Churches seek to deal with each other with a brotherly concern. This does not exclude extremely frank speaking to each other, in which within the Council the Churches ask each other searching questions and face their differences. But this is to be done for the building up the Body of Christ. This excludes a purely negative attitude of one Church to another. The positive affirmation of each Church's faith is to be welcomed, but actions incompatible with brotherly relationships towards other member Churches defeat the very purpose for which the Council has been created. On the contrary, these Churches should help each other in removing all obstacles to the free exercise of the Church's normal functions. And whenever a Church is in need or under persecution, it should be able to count on the help of the other Churches through the Council.
8) The member Churches enter into spiritual relationships through which they seek to learn from each other and to give help to each other in order that the Body of Christ may be built up and that the life of the Churches may be renewed.
It is the common teaching of the Churches that the Church as the temple of God is at the same time a building which has been built and a building which is being built. The Church has, therefore, aspects which belong to its very structure and essence and cannot be changed. But it has other aspects, which are subject to change. Thus the life of the Church, as it expresses itself in its witness to its own members and to the world, needs constant renewal.
The Churches can and should help each other in this realm by a mutual exchange of thought and of experience. This is the significance of the study-work of the World Council and of many other of its activities. There is no intention to impose any particular pattern of thought or life upon the Churches. But whatever insight has been received by one or more Churches is to be made available to all the Churches for the sake of the "building up of the Body of Christ."
None of these positive assumptions, implied in the existence of the World Council, is in conflict with the teachings of the member Churches. We believe therefore that no Church need fear that by entering into the World Council it is in danger of denying its heritage.
As the conversation between the Churches develops and as the Churches enter into closer contact with each other, they will no doubt have to face new decisions and problems. For the Council exists to break the deadlock between the Churches. But in no case can or will any Church be pressed to take a decision against its own conviction or desire. The Churches remain wholly free in the action which, on the basis of their convictions and in the light of their ecumenical contacts, they will or will not take.
A very real unity has been discovered in ecumenical meetings which is, to all who collaborate in the World Council, the most precious element of its life. It exists and we receive it again and again as an unmerited gift from the Lord. We praise God for this foretaste of the unity of His People and continue hopefully with the work to which He has called us together. For the Council exists to serve the Churches as they prepare to meet their Lord Who knows only one flock.