Why YSK: Beehaw defederated from Lemmy.World and Sh.itjust.works effectively shadowbanning anyone from those instances. You will not be able to interact with their users or posts.
Edit: A lot of people are asking why Beehaw did this. I want to keep this post informational and not color it with my personal opinion. I am adding a link to the Beehaw announcement if you are interested in reading it, you can form your own views. https://beehaw.org/post/567170
Last I checked, their reason for defederating is to avoid the high influx of new wildcard users from large instances without vetting processes.
As for the radical echo chamber part, I can’t say for sure because I didn’t actually interact with them but I recall the term they make you agree to apply for an account was somewhat vague, possibly allowing arbitrary bans to enforce an echo chamber.