But what happens (as did recently) when instances change direction? What happens (as did last year) where one instance admin had the wrong contact details for another so a message didn’t get through and ended up with an instance blocked and defederated for no good reason. What happens when an admin has an episode and gets in an argument that results in tit for tat blocks.
How can any new user know this might happen? How can they know what they are signing up for when descriptions are so brief?
Defederation is a good thing but unfortunately the people are human and fallible.