I wouldn’t hit you for a slur. I will write you off as a asshole. As for the South Park thing, the reveal is specifically calling put what you said about it sounding the same. Let’s preface this by saying I don’t watch much South Park, really just small clips like these to get context.
Additional context is understanding South Park likes to bring up social issues in offensive ways, which some find funny and others find distasteful. I’m pretty sure when it started it was just a joke, though one to make fun of shows with one black character. The retcon to me just feels like an evolution of the joke as humor, sensitivities, and acknowledgement of these issues grew. Plus hopefully the writers matured (as mentioned, I really only see popular clips so not sure).
To me, the way the Tolkien thing played out felt like it was similar to ManBearPig. The latter is technically a self own; they mocked climate change in the past and are now saying it’s true and they were wrong.
Is the apology genuine? I couldn’t say, I don’t know them. I’m willing to give them the benefit of the doubt though.