Meta threads will open federation to the fediverse soon, and while this is mainly to mastodon it will still affect lemmy. They are acting like they won’t be evil, but let’s be real this is Facebook when have they ever done that.
This article which has been trending lately explains some of the issues. https://ploum.net/2023-06-23-how-to-kill-decentralised-networks.html
This comment here is a simple analogy if you can’t be bothered reading the article. https://lemmy.ca/comment/5702922
When I last looked at the defederations of some Mastodon servers, everyone was already blocking Threads. This was a year ago. Instances running Lemmy and Kbin and like should probably do the same.