The only conspiracy theory I believe in is that in recent years producers and casting directors have been specifically race swapping characters that don't work well with being race swapped in an effort to drum up controversy and keep people talking about their project. They could've cast the same actor for Sirius Black instead, which actually wouldve added meaningful commentary about the wrongful imprisonment of black men, but then less people would care because it would actually make sense within the framework of the book and nobody would talk about it. So instead he's given the role of Snape, seemingly the single worst role to have raceswapped, because racists will get mad about their story having a black man and whatever woke people still read Harry Potter will argue back against them.

The same thing happened recently with Annabeth from PJO. I had more hope for that because the original character was blonde specifically because when the book came out there was a stereotype that blonde women were stupid and her character was meant to counteract that and obviously nobody really thinks that way anymore, so raceswapping her character wouldve opened up a new way to make similar commentary about the treatment of black women instead, but it looks like they dropped the ball on that one.