@simon_brooke New stuff doesn’t start with the W3C or any other big standards org. That happens after running code and roigh consensus (the slogan of the IETF) from bottoms up processes.
Right now I expect Mastodon and other codebases to evolve the the ActivityPub standard. It’s unclear how long that will take or who will sit at the W3C and speak for bottoms up community.
@boris You just bung an RFC to the IETF, and that starts the process. Mind you, they may bung it back at you if they think it isn't useful, I've had that happen to me.