I’d say it’s a big maybe on the protocol side of things.

In general it’s an affirmation of the power of open source software to grow and change things, which we’ve seen before. Mastodon was lying there ready as a more or less plug and play platform. That’s powerful in a moment looking for alternative platforms.

Mastodon’s success IMO isn’t necessarily a success for or an indication of success for ActivityHub. At most, I’d say, it attracts more attention to the idea of open platforms and decentralised social web infrastructure. But the specific protocol being used, AP, isn’t really a big part of the picture, and might just be the weakest aspect of the current fediverse story.

To illustrate, pebble chose not to federate their original platform because the task was too hard. Ask developers and they’ll tell how true this is. So it seems false to say that the protocol on its own is making open and decentralised social media happen. The heavy lifting is coming from the software devs making platform software.