Without wanting to take a stance on either side of these arguments, it does occur to me that, for this and other major FOSS projects deciding on AI policies, others can always start forks with different policies. The success or failure of such forks might even offer some insight into how helpful or harmful different forms of AI use are, at least from a programming perspective.

I'm waiting on this exact this to happen. Even in major projects there are AI proponents. They can start a fork for many reasons, experimentation, frustration or to try out an ambitious idea. It will take a bunch of time but we will get a very good insight into how much AI usage actually helps software development.