It can definitely be done badly, as in Hamilton and I guess Brigerton (I can think of other examples for sure) where it ends up overwriting and disguising racist history, but the alternatives are saying either just don't make these stories, make them but don't cast black people in them, or cast black people but every scene they have to be victims of brutal oppression. I think each of those would end up being more racist than just not being upset because of black people being treated 'white' where you might as well just substitute 'normal' because that's what that means in a filmic context

This actress might bring a specific take particular to her identity into this role, the movie might use it to make some race-related point, even as limplib as 'black women can be as regal as whites', or she might not and it could be totally race blind, either way its just a movie and ultimately the content is less important than the labor question of whether black people get a fair amount of roles