I have never been a fan of the Fox-Men movies (I liked the first and X-Men: Days Of Future Past. Other than that? Not so much) partially because the X-Men belong with Marvel Studios and partially because Fox takes too many liberties with the characters and some really epic stories.
And then there’s the fact that in a very real sense we’ve already seen Dark Phoenix, though then it was called X-Men: Last Stand.
And it’s a relatively underwhelming trailer (something it shares in common with the teaser). Not terrible by any means, but the X-Men were Marvel Comics’ premiere superhero team–I assume the Avengers currently occupy that space, though I don’t know for certain–and they deserve much, much better than we seem to get here.