If MegaCorp has massive $$$$, but everyone else has small $, then MegaCorp can sue anyone else for using "their" code, that was supposedly generated by an LLM. Most of the time, it won't even get to court. The repo, the program, the whatever-they-want will get taken down way before that.
Courts don't work by saying, "oh, but everyone is doing it! Not much we can do now."
Someone brings a case and they, very laboriously, start to address it on its merits. Even before that, costs are accumulating on both sides.
Copyright trolls are mostly not MegaCorps, but they are abusers of the legal system. They won't target Google, but you, with your repo that does something that minorly annoys them? You are fair game.