Protopresbyter John Meyendorff was a prominent 20th century Orthodox Christian priest, theologian, and writer. He was born into the Russian nobility as Ivan Feofilovich Baron von Meyendorff (known as Jean Meyendorff during his life in France).
East and West vie with each other in extolling the virtues and grace of Theotokos
‹…› the doctrine of the Immaculate Conception appears to the Orthodox theologian as not only absent from the biblical narrative, but also contrary to the biblical and traditional doctrine of the original sin. In the case of the Virgine's Assumption and bodily glorification, the tradition is formally preserved in Orthodox liturgical books and is very widely found in the patristic writings of the Byzantine Middle Ages. However, a definite uneasiness prevailed among the Orthodox with the proclamations of the dogma by Pius XII. The several, partly diverging, traditions which exist concerning the Assumption seem to them as belonging to a category of religious facts which essentially different from those subject to doctrinal definitions. Although Scripture itself records similar cases, that of Elijah, for instance, the absence of any reference to the death and glorification of the Virgin in the Bible seems to indicate clearly that these events played no essential part in the work of salvation as such. Consequently there was no need for the Word of God to recount them and quarantee their authenticity. The entire Gospel changes in meaning if Christ is not one but two distinct subjects, while it remains strictly the same whether the Virgin was, or was not, glorified in her very body after her death. The reserve, expressed almost unanimously by the Orthodox when the dogma of the Assumption was proclamed, does not presuppose and denial of the corporal glorification of the Vigrin, which is indeed testified by a fairly ancient tradition, for it certainly appears to be in conformity with the divine plan concerning which God "hath done great things" (Luke 1:49). But no theological necessity seems to justify its inclusion among facts which realized the salvation of mankind.
Christ in Eastern Christian thought
Ch.: The Meaning of Tradition, page 18
Thus, in spite of the opposition of the Orthodox theologians to the Roman dogma of the Immaculate Conception and their reservations regarding the new dogma of the Assumption of Mary — to the extent that this could imply that Mary did not die because of her Immaculate Conception — in spite of these differences, I say, which basically do not concern Mary herself but the doctrines of original sin and the Redemption, East and West vie with each other in extolling the virtues and grace of her "whom all generations shall call blessed."
The Orthodox Church: its past and its role in the world today
Ch.: Orthodox Faith and Spirituality, page 181