also since the Eastern Church believes she died first I see no reason to not trust them on this
My feelings exactly!
The Rock of Orthodoxy only spoke concerning the Assumption, that is the bodily and spiritual assumption of the Deipara into heaven.....NOT whether she died.
The Holy Spirit did not see it fit to go beyond this
dogmatically.
How fitting that the Patriarchates of the East (i.e. Antioch, Jerusalem, Alexandria, Babylon, and Cicilia) "complete" the dogmatic definition of the See of St. Peter.
And yet not dogmatically.
After all the other Patriarchates have no power to define dogma without an Ecumenical Council, only the Pope of Rome can speak from the See of Peter and define something outside of an Ecumenical Synod (however, even still Papal infallibility is meek compared to the way the Holy Spirit works in Ecumenical Councils, one could think of it as a safe-guard rather than the norm).
In any case this is an instance where we, as Catholics, must
breathe through
BOTH our lungs:
East and West. The Rock of Orthodoxy, which stands in the West, was given the grace to define the Assumption......the East, while not definitive, has kept the ancient truth that the Deipara actually did die.
There is no reason not to trust the East on this. I also cannot see how one can deny the death of the Deipara and stand well Patristically and even theologically.
(NOTE: All references to the "East" in this post are
solely refering to the Churches of the East that are in communion with the Pope of Rome).