Beehaw.org just defererated lemmy.world and shitjustworks, because of the open signups policy (as opposed to the waist high fence of a few paragraphs explaining why you're not an asshole)
To my understanding, Beehaw defederated with those instances due to an ongoing harrasment campaign by a few of their users. The open signups were not the reason they defederated, but rather a factor enabling the harrasment; the user(s) would be banned from beehaw, and inmediately make an additional account to continue harrassment. Beehaw has been pretty open about the how and why of defederation, and to my knowledge theyve been working with the admins of shitworks to get to a place where refederating is possible.
Thank you!