From the Vigil of the Ascension of the Lord:
When You were taken up in glory, Christ our God, while Your Disciples watched, the clouds received You in the flesh; the gates of heaven were lifted up; the choir of Angels rejoiced with gladness; the higher powers cried out, saying; Raise our gates, you rulers, and the King of glory will enter. While the Disciples, amazed, were saying: Good Shepherd, do not be parted from us, but send us Your all-holy Spirit, to guide and strengthen our souls.
O gracious Lord, when You had fulfilled the mystery hidden from ages and generations, You came with Your Disciples to the Mount of Olives, having with You her who bore You, the Maker and Creator of all things; for it was necessary that she who had suffered so greatly as a mother at Your passion, should also be filled with joy beyond measure at the glory of Your flesh. We too, sharing in the joy of Your ascent to heaven, O Master, glorify Your great mercy which has come to us.
To God, who appeared on Mount Sinai and gave the law to Moses, who saw God, and who was taken up in the flesh from the Mount of Olives, let us all sing; for He has been glorified.
The ranks of Angels, as they saw Your mortal nature going up with You, O Saviour, were astounded, and without ceasing sang Your praise.
As the Saviour had ascended to the Father with His flesh, the hosts of Angels were struck with amazement, and cried out: Glory, O Christ, to Your Ascension!
When You had filled the universe with gladness, merciful Lord, You took Your place with Your flesh among the powers on high.
As the Angels saw in the heights Your flesh now made divine, O Christ, they signalled to one another: Truly this is our God.
Let's also not forget that Christ's second coming will be "in the flesh". Does this mean that He will need to become incarnate again, as He was at the Annunciation? Of course not, as this would make a mockery of all that He did the first time around. Therefore, His second coming will be in the form of the Theanthropos, God-Man, as it was during His first coming, as also expressed in the Ascension hymnography. Examples:
O God, having renewed in Yourself Adam’s nature, which had descended to the depths of the earth, You took it up today above every rule and authority; as You loved it, so You made it sit with You; as You had compassion for it, so You united it to Yourself; as united with it, so You suffered with it; as not subject to suffering, yet You suffered and glorified it with Yourself. But the Bodiless powers were saying: Who is this man of beauty? Not man only, but both God and man, both together they appear. And so the astonished Angels flying in shining robes cried out to the Disciples: Men of Galilee, this Jesus who has gone from you as man and God, will come again as God and Man, judge of living and dead, granting the faithful remission of sins and His great mercy.
The Angels came and cried out, O Christ, to Your Disciples: In the way that you have seen Christ going up, He will come in the flesh as righteous Judge of all.
The men of Galilee, seeing You, O Word, taken up bodily from the Mount of Olives, heard Angels crying out to them, ‘Why do you stand gazing? He will come again in the flesh in the same way that you have seen Him.’
From this, there's no doubt that the Orthodox Church teaches that Christ did not discard His flesh after his Ascension, and, with regard to the Second Coming, will appear in the same flesh and human nature which He has glorified and perfected.