Look. I loved that stupid supplement, back in the days before I realized how very racist it was. And even if "everyone's a little bit racist", that's no excuse for people not to work on it.
GRRM got his start in fantasy during a time period where people weren't taught how many ethnicities were roaming around Europe. The place was never as white as people were taught it was. Thus, the sheer whiteness of fantasy. Do I think he's racist? No, I think he never thought about it.
However, that doesn't apply on a current day game. Claiming one is staying true to "the source material" when the author has said "Hey, that's actually a good idea" is still something to be called out. Out and out saying that people of color will not be included because the game runner doesn't want to is fucking racist. It's 2022 and there's no goddamned excuse for it.