AI code damages copyleft projects no matter what - we know that some projects are already accepting AI generated code, and they don’t ask you to hide it - it is all in the open.
I don't see how that follows or contradicts what I'm saying though. They could hide it, easily. Even if they don't hide it, how useful would it really ever be to only use the portions of the codebase that have been labelled as having been AI generated? Can one even rely on those labels? Making use of the non-copyrightability of AI output to copy code in otherwise unauthorized ways does not seem like a straightforward or legally safe thing to do. That's especially the case because high profile proprietary software projects also make heavy use of AI, it doesn't seem likely the courts will support a legal precedent that strips those projects of copyright and allow anyone to use them for whatever. So basically I'm not at all convinced about the idea that AI code damages copyleft projects, it seems unlikely to be a problem in practice.