You are both trying to make it sound like using AI to add features to Quake 1 somehow breaks the original GPLv2 license that Quake 1 was released with and makes the resulting modern engines illegal or something. It does not, please stop implying things like that.
That article describes the problematic scenario like this:
So similarly, if I use generative AI to add new features (new code) to Quake 1, the code of the new feature can be used by anyone in their non-GPL projects. Okay, cool. Why would that be bad if I don't care who does what with the AI generated code? Obviously if I was the GNU Project leader, I would not want that, because I don't want my code base over time to be made of more and more code that can be used under different conditions than those conditions that are the entire purpose of the GNU Project (to make free software). But I'm not GNU Project leader, I'm a Quake 1 enthusiast and I don't care, go ahead and steal the AI generated code. Me adding AI generated code to Quake 1 does not mean someone can suddenly steal the entirety of the original Quake 1 source code and create closed-source versions of it. Similarly, using AI to modify existing Quake 1 source code, it is still derived from the original Quake 1 code, so id software's copyright still applies, GPL still applies. There is no chain of events involving AI that would lead to eventually there being a Quake 1 engine that's closed-source.
