As long as we believe she was taken up to heaven body and soul, we can refer to it as death, but that is not very common. It is interesting also that Heaven holds at least three corporal bodies … Our Lord, Our Lady, and Elijah. Does this mean it is a physical location?
And Enoch. BUT, Elijah and Enoch’s being taken up are different.
They are not Glorified, nor strictly speaking in “heaven”…though it is the tradition of the Church that God lets them know our prayers and we can treat them like Saints.
But technically, Elijah and Enoch never died, and are being kept suspended somewhere, not like Jesus and Mary…but instead to be brought down during the Last Days as the Two Witnesses of the book of Revelations, suffer a glorious martyrdom, and THEN die and rise to glory like everyone else.
So Jesus-Mary is sort of a different situation than Elijah-Enoch. Christ and Mary have died, risen, and been glorified into their final state and have the beatific vision.
Elijah and Enoch were taken up to be preserved somewhere, true, and God reveals our prayers to them…but they have yet to return, die as martyrs, at that point attain heaven strictly speaking, and then rise at the general resurrection, which should follow quickly upon their martyrdom by antichrist.
So, bit of a different situation.
But Mary certainly did die. It was not part of the dogmatic definition, because no one ever questioned it. The document presupposes that she did, and though not officially defined extraordinarily as such yet, it is certainly the constant teaching of the ordinary magisterium and Tradition that she did die.
Roman Catholics emphasize the Assumption, Eastern Catholics and the Orthodox emphasize the Dormition. But both are part of the same mystery, and both are important Truths.