Fair enough, Linux-libre is technically an example of a fork. That being said, that project has a very specific goal of just removing proprietary packages and blobs, it's a lot more simple and direct to maintain. I don't know that you could truly do such a thing with AI/LLM tainted code without a hard fork and essentially no longer merging in from upstream. Vim Classic is trying to this right now, and it is a lot more doable since that's a much smaller project.