People realize there is more than one version of the Dark Phoenix storyline, right?
X3 drew from more than one of the takes on the story, and I have to believe filmmakers are aware of the other versions of the event for this adaption as well. While there will likely be some classic key beats explored, not every story point is going to come straight out of the original Dark Phoenix saga...nor has any comic book "event" adaption been that slavish.
-Jean's struggle dealt (or alluded) as mental illness
As opposed to what, a cosmic mental illness?
-The grounded vision of this story
This isn't unique to the adaptions of Dark Phoenix through, it's a staple of the entire franchise in many respects. The Last Stand was actually arguably one of the least grounded and most fantastic movies of the franchise, and if she's turning into a fire being.and they're going into space and there are aliens involved..how grounded is it, exactly?
-Eric being shoved in that storyline again
-Eric as the villain again
-Eric and Charles butting heads again
Again, these are not issues limited to their adaptions of the Dark Phoenix saga, this is a trend of the franchise in general; especially since FIRST CLASS.
-Jean killing a friend and member of the X-Men
Which thus far is a rumor, and if it's not, so what? Why is this an awful thing from a story standpoint?
And some other details like
-Kinberg repeating scenes from X3 but with different outcomes like Jean and Scott kissing. Or Jean almost killing Charles
Well, Jean and Scott tend to kiss in the X-Men mythology...this hardly seems like a big deal if it's an idea they use.
Jean and Charles fighting on the psychic plane is a staple of most versions of the saga, including the original. It would be kind of silly if the X-Men's resident psychic didn't attempt to resist a psychic threat, wouldn't it?
We know they have superhero costumes from set pictures.
-Jean using the same red coat
I'll believe she's wearing the same red coat when I see it. I don't really see the issue people have with the "red coat" (which isn't just a red coat...it's an entire red outfit. Can the thing she wears in THE LAST STAND really be called a "coat")?