no it will use activity pub for federation so it will be federated with lemmy aswell

I agree. Also, there is a ton of really great programming and AI/ML content on Twitter. I hope much of it migrates to Mastodon and Lemmy, and I'm starting to see some of it appear on Threads as well. Instead of knee-jerk reactions to defederate from Threads to avoid the the embrace-extend-extinguish that happened to XMPP, we should build technical safeguards to keep things open.

Although Meta's social media and privacy woes are well-known, Meta is one of the largest contributors to open-source and AI/ML. We should be encouraging companies to federate and building safeguards into ActivityPub to discourage "embrace-extend-extinguish". We're already seeing fracturing in the Fedverse between Pleroma and Akkoma, Beehaw defederating from lemmy.world and sh.itjust.works, and most Lemmy mobile clients not supporting Kbin. I want the fediverse to succeed, but this is driving users away—what's the point if this ends as a ghost town? Do we want to go the way of Identi.ca and previous attempts

This is called prevention. You know, how it's usually easier to prevent something bad from happening, rather than waiting for the bad to happen and then taking some action.

Will threads federate in the future? Maybe, we don't know. Will Meta leave it at that and not go after other ActivityPub systems, like Lemmy and Peertube? We don't know.