It’s bizarrely complicated in the way that lemmy handles it
D gets to look over the fence and see how much fun A and B are having without them and regrets their antipasto attitude?
yeah, I don’t know – personally think a ostracism metaphor would be a better match for federation – once A defederates from D, not only do they block anything incoming from D but they also don’t send anything out to D – D has to patch together posts from thirdhand federations …