Threads accounts will be available on Mastodon and other services that use the ActivityPub protocol.

I'm very curious how this will all shake out. I can understand all of you who want to block Threads and the only two instances that I am on myself are going to do exactly that, but it seems tremendously likely that the flagship instance of the fediverse, mastodon.social, will federate and it will have a massive impact on not just the culture, but also on the codebase. For example I wonder what services will go for feature parity and add features like voice notes which Threads added recently. Oh and culture-wise, with POTUS joining Threads, big institutions like the White House will suddenly appear on the fediverse.

Still holding out hope that a bunch of new users and new ideas will rejuvenate the fediverse, in any case 2024 should be a big year for it.