It didn't originate from them but it was popularized by them and the phrasing is certainly South Parkian. Ironically they've contradicted themselves on this argument by arguing that the n-word is never okay to say (while having a white character and a voice actor say it) and then arguing that using the gay slur f-word is totally okay because it doesn't mean anti-gay stuff anymore.

I think I first saw it in iDubbz's tana mogeau video; made in response of her criticising him for saying the n word. He makes a couple of fair points and pulls up evidence of her using the word but he also uses this exact talking point to justify his use of the word. It's funny because in the exact same video, he also makes the argument that context is imperative; which contradicts the above argument. I think the whole thing was more so an exercise in creating "youtube drama" as opposed to making any sort of cogent point about the nature of comedy and free speech.