Not an expert, just relaying what I read elsewhere. TLDR: “nothing goes in, nothing goes out between you two” is about right, but it’s not entirely symmetrical.
Instance A defederates from instance B. This means that (let instance C be a neutral third party that is federated with both A and B):
- no posts or comments by users from B anywhere on lemmy are visible to users from A
- existing posts and comments in communities on A are still visible to users from B
- new posts and comments by users from A and C in communities on A are not visible to users from B
- new comments by users from B to existing posts in communities on A are not visible to users from C
- new and existing posts and comments by users from A in communities on C are still visible to users from B
I’m plagued by visions of Dark Reunion stealing Black Beat, the unstoppable force that lives in my right arm.
But they will fail again, as they always have, for I am The Jet-Black Wings, protector of this world and I see right through their evil schemes!
https://youtu.be/zhBpp0yEQH0