If someone takes samples from a bunch of songs and mixes them together in way that sounds like a new track - that's creative, right? Wouldn't you apply that to some of what ChatGPT does? You can ask for a story with oddly specific elements and you'll get a story which has never been written before. It's becoming harder and harder to say it's not creative (even if you include the prompter as part of the creative process).
If you look at what songs are being written today, it’s quite different from what was written a hundred years ago. ChatGPT, on the other hand, would still create the same stuff a hundred years from now that it is creating now. (Same for Midwinter, etc.) What current AIs are missing, at the very least, is learning and exploration, and learning from its own learning and exploration.
People often argued that a Jackson Pollock style of artwork is not art because they just threw paint on a canvas.
Of course, Pollock did think about the process, there's more form to his works than that. Similarly, if you just arbitrarily mash music samples together you're unlikely to get anything that's really listenable music ... you need a little more for it too be creative.
Indeed, we often describe work as "derivative" when it's not particularly creative, it lacks spark. That seems like the definition of generative models. But then probably most human artwork is substantially derivative (in the art-critic sense).
If you provide "oddly specific input", then you've provided the creative seed, growing that seed is impressive work, but it is work with a different fundamental character.