Before LLMs programmers had pretty good intuition what GPL license allowed for. It is of course clear that you cannot release a closed source program with GPL code integrated into it. I think it was also quite clear, that you cannot legally incorporate GPL code into such a program, by making changes here and there, renaming some stuff, and moving things around, but this is pretty much what LLMs are doing. When humans do it intentionally, it is violation of the license, when it is automated and done on a huge scale, is it really fair use?