I disagree. For one, it's unenforceable, just like outright banning it.
But AI assistance can also mean a lot of different things, from outright vibecoding through autocomplete up to only asking it to so review. It diminishes the human work in the eyes of other people, because a simple disclaimer doesn't distinguish between the work done, and also encourages people to point out to AI as a scapegoat for their mistakes.
Good code always was and should always be one where a human is fully responsible for it; if you decide to vibecode and happens to end up with perfect code, good; if you write it fully yourself but it's crap it doesn't absolve you that you didn't use AI...
It's a tool, so use it responsibly like any other tool and stand behind your code no matter what tools you used.