Well, maybe. But there are overwhelmingly large numbers of people who want to be in a fandom, and that means being fans of some shared thing. Maybe that shared thing will be AI generated, but it won't be a world of solipsists.

I think what the person you’re responding to meant was that you can generate a fandom for the content that was generated for you. So, you can get the feeling of being in a fandom despite there being no actual other humans that know what you’re talking about.

Sure, and people might enjoy that, but I'm saying that as much as people want to have fans, people also want to be fans, and that's not compatible with everyone consuming algoslop generated for them personally. Nobody is going to walk around with a T-shirt for an algoband that has an audience of just themselves. Maybe a virtual band gets famous in the same way Hatsune Miku is famous. But that's not personalized generation, that's just an old fashioned band with different tech.

A world without fandom is one without sports. That seems deeply unlikely to me! Anyone can generate personal podcasts with NotebookLM, which people enjoyed for a bit but doesn't seem to have made any impact on actual podcasts at all.