You really need to share your time travel secrets with us some time, because you sure seem to know a hell of a lot more about how the movie turned out than the rest of us do.
You definitely can't be going by the trailer and the information revealed online so far, because none of that has really given us any ideas what the characterizations are going to be like.
Just because it's a horror movie set in a some kind of hospital or asylum, doesn't mean the characters personalities and back stories won't still reflect the comic versions. But then again you've obviously been to the future and seen the movie already so I guess you would know better than I do.
Oh yeah, because FOX has a great track record with keeping the X-Men characters close to the comics

Generally I'd be one of those people, because I'm a big X-Men fan and I even kind of liked Apocalypse even if it is mediocre. But between the abomination that is Logan, and giant "fuck you" of TV shows like Legion and The Gifted, I officially have no more reserves of patience for the moronic actions of FOX. I like the real New Mutants, and I'm done seeing FOX ruin every fucking character they got in that deal with the devil Marvel made with them all those years ago. When I can watch the movie for free, I'll see how badly they butchered great characters because god knows FOX butchers good superheroes better then anyone else not named Zack Snyder.
It doesn't take a time machine to see any of this, it takes the bare minimum amount of common sense needed to, say, not try to breathe underwater to figure out what FOX is doing at this point.