AIs are not human and therefore their output is a human authored contribution and only human authored things are covered by copyright. The work might hypothetically infringe on other people's copyright. But such an infringement does not happen until a human decides to create and distribute a work that somehow integrates that generated code or text.

The solution documented here seems very pragmatic. You as a contributor simply state that you are making the contribution and that you are not infringing on other people's work with that contribution under the GPLv2. And you document the fact that you used AI for transparency reasons.

There is a lot of legal murkiness around how training data is handled, and the output of the models. Or even the models themselves. Is something that in no way or shape resembles a copyrighted work (i.e. a model) actually distributing that work? The legal arguments here will probably take a long time to settle but it seems the fair use concept offers a way out here. You might create potentially infringing work with a model that may or may not be covered by fair use. But that would be your decision.

For small contributions to the Linux kernel it would be hard to argue that a passing resemblance of say a for loop in the contribution to some for loop in somebody else's code base would be anything else than coincidence or fair use.

Same as if a regular person did the same. They are responsible for it. If you're using AI, check the code doesn't violate licenses

Tab complete does not produce copyrightable material either. Yet we don't require software to be written in nano.

If the output is public domain it's fine as I understand it.