The thing is, many of these guidelines are related to finalized products fully created by AI. As in, the AI produced a written or drawn work at the end of it that on it’s own is the product (Eg. an article or an image). This will probably apply to code in some reasonable way, but at the end of the day there’s only so many ways to write code since it’s syntax and not as flexible as language. It actually has to produce something that works, so there are far less finite arrangements.
If you were to compare code written by two people at two companies, doing a very similar project, you wouldn’t be surprised to find two pieces of code doing almost the same thing in the same syntax, barring synthetic sugar like naming and coding conventions. Neither will likely have violated the other’s copyright since simultaneous invention is a thing. And if they happened to have similar prior experiences, it’s even more likely.
Likewise, the way the code was incorporated into a project as a whole might sufficiently constitute a human contribution, and perhaps even the more important contribution. You likely wouldn’t retain the copyright on the specific snippet, but rarely are small code snippets enough on their own to claim copyright over to begin with. It’s the program or library or system as a whole that’s the finished product.
I’m kind of torn on this, because on the one side I can see the developer’s troubles. If they have 30 years of experience and they considered the impact of using it they will most likely know how to use it properly and ethically. Indeed many of the issues people have with AI are a kind of redirected anger, when really they are issues with capitalism, incompetency, or digital illiteracy. And the person posting the issue seems purely there to fan that flame rather than actually contribute. Something maintainers could use just as little as slop authored PRs.
But on the other hand, being open about the usage is a must. It’s the price to pay for going against the grain. If your ideals and means are pure, they should be defendable and scrutinizable to reasonable people, and there should be no issue with that in the long term. Hiding the usage will create doubt about authorship, and make defenses harder to point at, while it won’t stop the horde.