The GPL talks about "the preferred form for modification of the software", and I'm starting to think that anything which involves any kind of LLM agent should be including all the text that the user gave to it as well. Prompts, etc.
Of course, even then it's not reproducible and requires proprietary software!
I still think the source code is the preferred form for modification because it is what you point the AI at when you want it to make a change.
Sure there might be md documents that you created that the AI used to implement the software, but maybe those documents themselves have been AI written from prompts (due to how context works in LLMs, it's better for larger projects to first make an md document about them, even if an LLM is used for it in the first place).
As for proprietary software, the chinese models are not far behind the cutting edge of the US models.
Except the GPL is dependent on the author having copyright over the original software but the output of an LLM may not be covered by copyright as a derivative work.
Of course, even then it's not reproducible and requires proprietary software!