You're missing that an AI ban is actually just a poor quality AI ban. No one can tell if you used AI in a quality way and write the description in quality English. All this ban does is filter out the worst slop that would never have worked. People can and will still submit quality PRs that used AI, but no one will know it used AI, because the author was conscientious.

I don't know, once you ban AI-assisted coding outright, it's much higher likelihood this ban will cause the Godot team to spend time and energy being AI detectives, especially if they don't agree with the intent of the contribution.