Just going to toss my $0.02 to some of the conversations going on here:
Jean manifested/summoned the Phoenix Force at the end of Apocalypse. It may not have been a 100% manifestation, but it was the Phoenix. What we don't know is if it sticks around between movies, slowly building until the incident in space or if it goes dormant again until its presumed complete/total manifestation during said incident. We'll just have to wait until the movie comes out to see.
As for Storm holding an umbrella, that's a 100% nitpick. It's not a slap in the character's face, disrespect or any other overly dramatic interpretation. That'd be like if I said they totally disrespected Iceman because his costume involved him wearing a coat. Don't get me wrong: you have the right to complain about it or whatever else you want, but don't expect to not be called out for it.
As for costumes, we'll see if they keep the ones from the end of Apocalypse or tweak them a bit. I'd wager on them being tweaked, but we'll have to wait and see.
Still psyched about the Zimmer news.