I think they changed to fit the genre of the musical no? Like yeah you could have had a bunch of white guys rapping, but I feel like it would have hit different. It does bring up the question of how is it ethical to race swap a historical figure? Particularly when the race of that figure doesn’t necessarily play into their core story or struggle.
I haven’t found a lot of historical or fictional white characters where their race specifically plays into their story. There are some… like Elle Woods in Legally Blonde. The fact that she is a blonde, seemingly ditsy, white woman plays into why people underestimate her. I keep trying to build that list though because I hate to see when people are like “Why not race swap Rosa Parks or Black Panther then?” Because the fact that they were/are black is part of their stories. You know what I mean?