“Threads” is a new thing and allegedly he intends to have it link to the fediverse.
The thing to worry about is that it is an attempt to get rid of the Fediverse via Embrace, Extend, Extinguish.
Since Threads is directly tied to Instagram, it may be an attempt to have the majority of fediverse users use Threads, because only Threads is also tied to Instagram. Once having the majority, defederate and keep the majority of the users that couldn’t otherwise be bought.
This is hearsay mind you. I am repeating what I have read. Please feel free to seek more accurate info.
The Tl;dr: Zuck is scared of unbuyable competition and we should NOT welcome his product in.
Side note: I can’t see the word “Threads” like I can Facebook or Twitter. Threads already exist as a term for a certain format, not a social networking service.
Metas new Twitter competitor Threads claims it will connect to the fediverse eventually, it doesn't yet. If Threads does then I expect he'll use the old microsoft "embrace, extend, extinguish" tactic. Add extensions to ActivityPub that only the the threads client and server support in the hope that Threads client becomes the dominant way to access the fediverse then when all the clients give up, he can drop support for it.