[Bainbridge]

No, not quite. The Marian statements are not essential Christian beliefs.
Those would be Roman Catholic beliefs.
Unless, of course your point is that only Roman Catholics are Christians

[AzaleaCity5691]

Actually, those are beliefs of all rites of the Catholic Church, and, my assumption is, they are also the beliefs of all Orthodox Churches.

One day, all the rebels against the true church will rejoin her. This must come to pass before the return of Christ, as it will be this unified Christian church that is to be persecuted in the last days.