Board Thread:News and Announcements/@comment-238662-20140522094123

Basically, at the end of Days of Future Past, Wolverine creates a new timeline so everything up to the point where Wolverine changes the past then splits into two different universes. The first universe is all of the films we've already seen so First Class, Days of Future Past 1973 before Wolverine changed it, X-Men Origins: Wolverine, X-Men, X2: X-Men United, X-Men: The Last Stand, The Wolverine. And then the second universe is First Class, Days of Future Past new past, X-Men: Apocalypse.

So basically, there are two different universes, Earth-10005 and the currently undesignated new Earth. Therefore, people should not edit the Jean Grey or Scott Summers or Henry McCoy articles to say that those characters are alive because they aren't because the current articles are for the Earth-10005 characters not the new universe that retcons many of the films. 