This is arguably just a form of arguing for "death of the author". When you release a creative work, in some form, that work is no longer just yours. The audience receives, experiences and interprets that work in their own way. While the author maintains some degree of "canonical" control over the work, once its in the open, the audience can (and does) do what they will.

We aren't exactly consistent with how we approach this either. For example, I agree that reading "GPT-5 will autocomplete [GRRM's] series" feels "wrong" in the same way that if Terry Pratchett's "Disc World" series was "continued" by some non-approved author that would also feel wrong.

But contrast that with something like Star Wars, when George Lucas dies, I don't think anyone is going to feel any strong discomfort with some random person writing new Star Wars stories, even if those stories use the canonical characters. I suppose Disney might have a problem with it, but as a society, I don't see very many people losing sleep over someone not licensed by the Disney corporation writing more Star Wars. Likewise Star Trek. Gene Roddenberry is long gone, and while Paramount has ownership of the IP, if someone wrote their own Star Trek stories, no one is going to feel like they don't "comprehend the distinction between art and fan fiction".

And for further contrast, consider IPs that are well and truly part of the public domain. Cthulhu was the work of one author but since his death the lore has been expanded by multitudes of people, and no one finds that distasteful or tone deaf. No one thinks the "Hades" or "God of War" series of games don't qualify for "art" because the characters and lore being written about were the works of dead authors and the new material is certainly not "authorized" by those authors or their descendants.

Obviously time and distance plays a part of this, but as a more contemporary example, I wonder how many people would lose sleep or feel any significant discomfort over unauthorized or even AI generated Harry Potter works, either now or post JK Rowling's death. At the very least, if this quote read that Gogineni would "rest easy knowing that even though JK Rowling has [lost the plot/is an awful person/pick your reason for disliking her or her later work], GPT-5 will autocomplete her series." would that make people as equally uncomfortable? In my estimation, I would guess it would fall somewhere between the GRRM version and something like new Star Wars material for most people.