This is tricky, though, because that LLM was likely also fed code with a license incompatible with the AGPL. So in theory, that code (whether source or compiled) may not be distributed under any license at all.

Being hard to solve doesn't make a problem go away, though. This is a place where I'm somewhat curious where it ends up. Frankly I think the outcome is more interesting for artistic works (e.g. poetry or images) than practical ones like code, since current generations of AI seem so much better at the former. Still interesting either way.