I think it'll be someone pushing the boundaries of hip hop/rap/etc., it feels like there's still a lot more experimentation and unexplored stuff that can happen there. And most of the people on HN probably won't really appreciate it much, just like the general population didn't quite fully appreciate Brian Wilson's genius back when he was doing his best work.

I'm not super close to that genre so I wouldn't dare hazard a guess who that might be.