I have mixed opinions on the "AI=theft" argument people make, and I generally lean towards "it's not theft", but I do see the argument.

If I put something on Github with a GPL 3 license, it's supposed to require anyone with access to the binary to also have access to the source code. The concern is, if you think that it is theft, then someone can train an LLM on your GPL code, and then a for-profit corporation can use the code (or any clever algorithms you've come up with) and effectively "launder" your use of GPL code and make money in the process. It basically would be converting your code from Copyleft to Public Domain, which I think a lot of people would have an issue with.