As long as they don't distribute the model's weights, even a strict interpretation of the GPL should be fine. Same reason Google doesn't have to upstream changes to the Linux kernel they only deploy in-house.
But wouldn't that be like some company using gpl licensed code to host a code generator for something? At least in a legal interpretation. Or is that different?
I mean, is the case you're making that you can run a SaaS business on GPL-derived code without fulfilling GPL obligations because you're not distributing a binary?
