Did you ever consider the black woman who plays Hermione Granger in the play was chosen not because she’s black, but because she’s actually good at her job, which is acting? That possibly she was chosen because she was the best fit for the character in the auditions?
I remember the same complaints when the Lightning Thief movie and Legend of the Seeker show were released, with characters whose race was never at any point in the books described, nor was their race of any importance to the story, and complaining, “but they made them black!”
As far as the seeker, seriously, absolutely no importance could ever possibly be placed on his skin color, he’s just an excellent warrior who’s good with kids, especially since he calls them ugly.
Grover was even better, as he was described as having curly dark hair, which is a bit more common among black people than white, so the closest Riordan ever came to describing Grover’s race put him much closer to black than white.
So in both cases, and this one, all those people complaining about changing races, “for the message”, and SJW bullshit? They’re the biggest fucking social justice warriors out there, they just have a different opinion from a lot of others about what is socially just.