Why not? Because it’s not obvious or because you know, unequivocally, that it’s not happening. Just because you can’t tell there’s a problem doesn’t mean there isn’t a problem.
Now, if only black people/people of appropriate decent are playing black characters, then there’s no issue. If that isn’t the case, regardless of if you can tell or not, it’s a problem. The knowledge that that occurred with Skelator last year definitely doesn’t help the problem.
True, I don't know exactly 100% what's going on behind the scenes, just what I've seen on video and in person. I do think the choice to use masks in this maze was a poor one for sure. Especially given the size of the talent pool available in Los Angeles.