They're probably NOT going to give her her "iconic" suit. First of all, it being "iconic" is not a valid reason to use it in a movie in and of itself. WW has an "iconic" costume, that would look really stupid in live action. You do not want your actress to be embarrassed to wear their costume and having Carol stand alongside her fellow (fully clothed) Avengers teammates in what is essentially a one-piece swimsuit and thigh-high stripper boots would not send a particularly good message. It also doesn't even remotely fit her character. No, the fact that Marvel is pushing her in the comics a certain way, combined with the movie being called CAPTAIN Marvel, points to them using a variation of her current look, which is the best choice imo.