The "blocking" happens on the side of the AI users. You like using AI. You are aware of this policy.

Will you submit an AI-generated pull request to OpenJDK? No? Voilà, you have successfully self-enforced the OpenJDK policy.

Or do you go to the trouble of finding an interesting issue to work on, get your agent to code it up, manually polish it to make it less AI-looking in case there are doubts, and then submit it? Yes? No. Why would you? To prove some kind of point, to yourself, that you can never disclose publicly? Most people have better things to do. Voilà, the policy is, again, self-enforced. Enjoy your day at the beach instead of trying to trick a project that is politely asking you not to trick it!