Since he is your uncle, you have an inroad available of meeting him to hopefully patch things up. But be aware that you might have to try and understand his point of view rather than labelling it, and writing him off as a bigot.
I don't know the full story, but I've become somewhat skeptical when I hear things like this.
E.g., "He was a druggie!" Yeah, no. It was Percocet, because his hip was profoundly fucked up from all the jumping around on stage he'd done for decades. As a Jehovah's Witness, drug abuse was strictly against his faith, and he didn't even allow guests at Paisley Park to drink or smoke tobacco. That kind of thing.
See how making an assumption about someone and proceeding with that as a premise leads to mistaken beliefs about the events in their lives?
In your post you suggested that your uncle was saying racist things. You imply his racism and I bet it comes across quite strongly when you speak/type.
Worse than passing judgement on someone is passing judgement and then communicating it passive aggressively. Word games, used so that the other person can't properly address what was said.
My feed is a lot less unpleasant now, but we're both that much more isolated in our echo chambers. Granted, I think the acoustics are much nicer in mine, but a breadth of discourse does, one hopes, help to keep one's mind ... if not more open, at least more aware of what other people are thinking.