I think you describe it really well. There is certainly a large pocket of black communities on social media sharing dreams of a Western takeover, ranging anywhere from outright (fraudulently) claiming inventions they never invented, brazenly replacing characters in every form of entertainment, all the way to openly proposing a white purge, let's call it. Very concerning.
What's even weirder is that this content was rarely ever flagged in the Twitter days, and still prevails on X today. Demonizing anyone of white European descent on Reddit is also completely acceptable, and doesn't result in moderation.