Icons of the dormitions of other saints, such as Ephraim the Syrian, Anna the mother of the Mother of God, Irene Chrysovalantou, and others, show the saint's soul being taken to heaven by an angel.
The iconography of the Dormition of the Mother of God, as well as the hymnography I quoted in an earlier post, features Christ taking the soul of His mother as a babe in swaddling-clothes Himself to heaven, not even entrusting it to angels. This is all fitting and proper for the woman who is "more honorable and more glorious than the hosts on high". Nothing less would do.
This motif, therefore, proclaims the bodily death of the Mother of God. The soul is separated from the body at death, is it not? This destroys any notion of her being bodily assumed into heaven without dying first. As for Apostle Thomas arriving three days later than the others at her tomb, and finding it empty, this simply says that her body was assumed into heaven, something that is also expressed in the hymnography. The dead body of the woman who was spared bodily corruption and destruction while conceiving, bearing, and giving birth to God Incarnate, was again spared corruption - the corruption of the grave.
Was she physically resurrected before ascending, as Christ was? I don't believe Orthodox Tradition has ever taught this. Was her body and soul reunited in heaven? Perhaps. Perhaps not. It's a mystery, and we must be content to leave it at that. What we do know is that she stands closest to the throne of God, alive in Christ as are all the saints, and she, with a mother's boldness, unceasingly intercedes on our behalf to her Son and God.