I haven't been following the Threads stuff too closely so I didn't realize they were planning to federate it. Interesting that one of the big social media companies is trying to get into this and I'm curious what that's going to look like.
Already considering just adding Threads to the blocklist but we'll see how it goes.
Being honest, they're probably only saying it because "fediverse" is the current buzzword. If they do wind up doing fediverse integration (assuming they don't ditch it for the next buzzword); I'd be prepared to bet it'll be a closed garden where Threads instances are only able to federate with other Threads instances.
I'd also advise blocking Threads; if nothing else than for the fact that some instances are talking about defederating any instances that federate with Threads.