I would not be at all surprised if Github adds a first party reputation system. It would be a clever way to increase network effects - imagine if you host on Codeberg you're inundated by AI PRs but on Github you can easily filter them out.

I can't see those pull request limits working very well. It's like trying to filter email spam by just rate limiting people. It's going to be annoying for the people you actually want to talk to, and you're still going to get at least 1 spam message from every spammer out there.