You can't have it both ways. There is s lack of latino X-Men and the most high profile latino/latina X-characters we have are ones that aren't actual X-Men, like Roberto and Rictor & ones who are obscure like Cecilia and M. So we either make them X-Men from jump (because this is an adaptation, liberties are going to be taken) or we change an existing X-Man member to be latino. The problem needs to be resolved one way or another.
And a lot of these minority characters are not interchangeable. Characters like Bishop, Sunspot, Psylocke etc serve a specific story or arc that needs to be properly established first. So it's not as simple as "Throw Bishop up in there for black male representation". Bishop's presence needs to be justified by the story first.
Well, I don't see it the same way. To me, staying true to a character does not mean making sure they stay straight or white. Their skin color and sexuality are not why I fell in love with them as characters. A non-white Cyclops, Iceman or Beast -- or a gay Hank/Warren would only enhance the narrative that the X-Men franchise has built it's foundation on.