There is nothing far fetched about this. GNU is an ideological organization and their ideology is "free software." Free software exists because of the copyright system. Now imagine if someone can just fork your GPL licensed software and distribute it under an incompatible license, and when you go to court, the judge tells you to punch sand because your codebase is all AI generated and therefore not copyrighted.

I am not saying this is not what will happen — the actual law seems to be still up in the air. But if it does happen it will be an existential threat to the GNU and the whole free software ecosystem.