I think it is an odd choice to put Jean in the Marvel Girl costume. However, I am glad that she is in green. I did not really like the X-men Red uniform (and no disrespect to the artist who designed it because I am a big fan of his). I just did not like the colors of the X-men Red uniform nor did I like the call back to the 90's.
It does give Jean a youthful appearance being in the mini-dress. I also wonder if we will continue to see Jean in a very passive and pacifist role (how can you really fight in an outfit like that - not that a psionic needs to actually fight mind you).
I hope Jean does get a new costume after these miniseries. We don't know if Jean will be a major player in whatever comes next. I wonder what Hickman feels about Jean Grey. I hope he answers a Jean related question for the next X-men Monday but my fear is if he does answer a Jean related question it will be about Scott and Jean's relationship. It seems to always go back to that but we should want the creators to see Jean as her own character and not an extension of Cyclops (but I fear that is will never happen).
I am very excited for Hickman. The other day I went to the comic store (hadn't been there in about a month). I spent too much money on comics and when I read through them I regretted spending anything. They were mostly Age of X-man (I do like Prisoner X and Apocalypse and the Xtracts). Jean is in the main book but yet I find Marvelous X-men to be the weakest of the Age of X-man titles. I think Age of X-man could have been something great but about 4 issues into each book and every issue feels like the same issue (maybe this is the style of comics now after all Phoenix Resurrection felt very much the same way).
Tomorrow we are hoping will be a Jean centric issue. We shall soon find out.