I saw threads here and on another post. What is "threads"?

A fascinating take on it. I'm still wary about Threads interoperating with the rest of the Fediverse, and how that may change the culture as well as the system over time (Meta would have the power and money to throw around regarding changes to ActivityPub implementation), but I also see it similar to email. And I've spoken about this before to the point I sound like a broken record ..

But people understand the basics of email. They understand they can sign up for a Gmail account and send an email to anyone else. Maybe Threads will be our Gmail here, and introduce people into the idea of a wider open social media concept in a more familiar way to them, and they can branch out as needed or just choose to stay on Threads.

In any case, any given instance can choose to block Threads if they so choose.