All vibe coded projects are in the public domain by definition.

The question is if the massive copyright infringement that all the major labs engaged in means that all work derived from llms is under the copyright of the original owners of the work.

It is quite possible to keep track of what piece of training data changed the value of what weight to the point that the activations for any piece of code can be attributed back to the original copyright holder, including the random initial values which are public domain. I've done this on a toy project for gpt2.