“Threads is deepening its ties to the fediverse, also known as the open social web, which powers services like X alternative Mastodon, Pixelfed, PeerTube, Flipboard and other apps. On Wednesday, Meta announced that users on Threads will be able to see fediverse replies on other posts besides their own. In addition, posts that originated through the Threads API, like those created via third-party apps and scheduling services, will now be syndicated to the fediverse. The latter had previously been announced via an in-app message informing users that API posts would be shared to the fediverse starting on August 28.”
On a technical level, no. You’re right. It would not be possible to capture the protocol entirely. But meta has serious cash to spend on marketing Threads. If they can capture enough of the ActivityPub market and were to collab with Bluesky and use their protocol (I forget the name), or make their own, it’s only a matter of time before the drop activitypub and force users either to join threads or lose access to their users.
Threads and Bluesky are kind of an existential threat to ActivityPub given Meta and Twitter’s track record with Open Graph, bootstrap, and public api’s.