Do you honestly think that context will matter legally, whether the dead “person” is talking/singing about love or their own death?

Yes, there is legal relevance to whether a reasonable person would interpret the remarks as really being from George Carlin, thus painting him in a false light, and the whole concept of George Carlin riffing on events occurring after his death (plus the disclaimer preceding the video and in the description) is relevant to determining that.

When I say copyright, I mean in a general sence. Infringement of IP might be a better suited phrase, but I assumed the synonymity was implied.

I don't see how this tracks. Consider your following comment:

You’re either too dumb or stubborn to even google what “transformative work” is. Typical “AI” techbro."

Surely that's a reference to the character factor of fair use, a defense specifically against copyright infringement? It's not a term used in trademark law as far as I'm aware for example (and "George Carlin" is not a registered trademark anyway).

Were you just referring to, and telling them to google, the broad layperson definition of "transformative"? In which case I think you've misunderstood their comment, because I'm pretty sure at the very least they were referring to the fair use factor.