Meanwhile, the vast majority of content OpenAI used to feed its AI models were not produced by OpenAI directly, nor were they obtained under permissive license.

That's input, not output, so not relevant to copyright law. If your arguments focused on the times that ChatGPT reproduced copyrighted works then we can talk about some kind of ContentID system for preventing that before it happens or compensating the creators of it does. I think we can all acknowledge that it feels iffy that these models are trained on copyrighted works but this is a brand new technology. There's almost certainly a win-win outcome here.