before they end up with a seat on the activity hub team. Then we’re back where we started.

There is no activity pub team. There is an informal group discussing enhancements at https://socialhub.activitypub.rocks but anybody can join that and submit proposals. Any nobody is required to accept or implement those proposals. I have joined the forum and submitted a proposal myself, but nobody has implemented it or even seems likely to.

Also, not blocking threads doesn't make your instance a "meta controlled instance". Meta has no power over any instance other than Threads. Even instances that don't proactively block Threads can't be forced to use any hypothetical Meta extensions to AP. And its really unlikely that people who started servers on a minuscule network (most likely for fun or philosophical reasons) are going to follow Meta's lead just to have access to more people. Everyone who is here and everyone who started a server here knowingly did that on a network that is a tiny fraction of a percent of the size of other social networks; an increased userbase isn't some big reward for fediverse server admins.