It has to be more than simply being subversive. Going from playing a straight up version of a pre-existing genre to a straight up version of another pre-existing genre, regardless of your intentions, doesn't make your output in the later genre avant-garde, so Dylan wouldn't qualify. It also has to have new ideas in the mix. Which at first that's what punk and hardcore were: a new sound that advanced music and had a subversive edge to it. Then it became bound by it's own genre tropes, and most modern punk and hardcore wouldn't qualify as avant-garde (unless they do things to subvert the tropes, like the Blood Brothers did), much the same way that Radiohead milking a sound that was done 30+ years before them can't be considered avant-garde, either.