You completely missed the point I was making. Or maybe I just didn't make my point all that well.
My apologies, dear NorthernPines. It was simply that when I read this I took it at face value and thought you were saying that the belief is not required of the Orthodox...
Most Orthodox believe in the Assumption (in some form or another) but it's nothing that is required.
To offer a beautiful quote from Bp Kallistos Ware's The Orthodox Church
Orthodox are not willing to take part in a ‘minimal’ reunion scheme, which secures agreement on
a few points and leaves everything else to private opinion. There can be only one basis for union
— the fullness of the faith; for Orthodoxy looks on the faith as a united and organic whole.
Speaking of the Anglo-Russian Theological Conference at Moscow in 1956, the present Archbishop
of Canterbury, Dr Michael Ramsey, expressed the Orthodox viewpoint exactly:
‘The Orthodox said in effect: ‘…The Tradition is a concrete fact. Here it is, in its totality. Do you Anglicans
accept it, or do you reject it?’ The Tradition is for the Orthodox one indivisible whole:
the entire, life of the Church in its fullness of belief and custom down the ages, including Mariology
and the veneration of icons.
Faced with this challenge, the typically Anglican reply is: ‘We would not regard veneration of icons
or Mariology as inadmissible, provided that in determining what is necessary to salvation, we confine
ourselves to Holy Scripture.’ But this reply only throws into relief the contrast between the Anglican
appeal to what is deemed necessary to salvation and the Orthodox appeal to the one indivisible
organism of Tradition, to tamper with any part of which is to spoil the whole, in the sort of way
that a single splodge on a picture can mar its beauty.
(‘The Moscow Conference in Retrospect,’ in Sobornost, series 3, no. 23, 1958, pp. 562-563).
In the words of another Anglican writer: ‘It has been said that the Faith is like a network
rather than an assemblage of discrete dogmas; cut one strand and the whole pattern loses its
meaning’ (T. M. Parker, ‘Devotion to the Mother of God,’ in The Mother of God, edited by E. L. Mascall, p. 74).
Orthodox, then, ask of other Christians that they accept Tradition as a whole....