That has been the point of this thread all along. Roman Catholicism DOES require belief in the Assumption of Mary as ex cathedra doctrine and those who do not believe it are anathematized, cut off from communion and, according to the CCC, unable to be saved. Those who are excommunicated - correct me if I am wrong - cannot go to heaven when they die as long as they die in that state.
If it all was just a matter of personal choice whether to believe the teaching or not, it wouldn't be an issue and there probably wouldn't be a thread on it - though I think it is an interesting point that two prior popes called heretical the ONLY writing that could have been a historical source for the belief. Without that, there IS nothing to base the dogma on other than wishful thinking of some people centuries afterward. Don't you wonder why the Apostle John never mentioned Mary's death in any of his epistles seeing as Jesus entrusted her care to him? His last book was written towards the end of his life and Mary was already long dead by then. If there had truly been a miraculous ascension of Mary to heaven, why wouldn't he have said anything about it? I think these are legitimate questions and are not asked just to tick Catholics off.
Bears repeating.......