I liked Letitia Wright in the first movie, but I've been doubtful that that character could transition to a legit Black Panther. Don't know much about Coel, but she does favor the comic book Shuri more when it comes to looks. In many ways Wright's Shuri is a lot more likeable than comics Shuri. She has personality, a nice sense of humor, and complimented T'Challa well, whereas comics Shuri had more of an edge, more insecurities, and was always kind of waiting in the wings, waiting for her turn. Wright's Shuri was unbothered in that sense. So even if they did make her Black Panther in the sequel it would be interesting from a character standpoint because she didn't want the job to begin with, so how does she cope with this new responsibility or burden. That's different than a chomping at the bit character ready to prove themselves, like comics Shuri or MCU's Wasp.
However if they do make Coel the new Shuri and let Wright go right now I don't know if I would support this. Evangeline Lilly also had made an 'anti-vax' statement or something months ago, for which she's apologized, and there's no speculations or rumors about her being replaced. And perhaps this is all just the media trying to stir up some mess. In any event, I don't think Wright should be penalized for having an alleged 'anti-vax' stance, if that's what results in her being let go from the MCU.
Changing Terrence Howard (who was in a relatively unimportant role in the first Iron Man film, or non-comic book fans anyway) with Don Cheadle (another, and arguably more popular actor) wasn't too big a deal, but if Marvel changes Shuris while making Coel the heir apparent and next Black Panther, that's going to be a very big, risky move. And if the movie isn't stellar (however much the media will try to sell it) then it augurs the fall of the MCU (and the decline might already be happening when you look at Black Widow's box office).
