I think you have to look at the context of white people saying it in battles before you start worrying about it happening more often. Casper said it by mistake, it just seemed to slip out for whatever reason. Skeletor said it deliberately as part of his bars and Kollision said it as a rebuttal to another racist comment. I think when people start using it like any black battle rapper would (i.e just as another word) that's when it gets out of hand, but aside from what skeletor did it's either been non deliberate or an extreme rebuttal to something else. None of them are ok, but I don't think it's a sign that it'll start creeping into white peoples battle rap vocabulary either.