I keep seeing people say that defederating from a server means your site will still send content to that server, but I don't actually see that happening in practice.
It also doesn't really make sense from a systems point of view.
If I have a server block list, that list is really only acting locally. Any site I put on that list doesn't know its been blackballed. Instead, I just refuse to accept content from it. Importantly, this is a refusal of delivery, not a stop request. When receiving content from remote sites, your site isn't actively making update requests. You basically just add yourself to a mailing list, and you and your instance get sent anything that you've signed up for. So, stuff keeps getting sent even even after your instance has defederated, it's just being filtered out before it reaches you.
But if I've blocked communications with another website, I've blocked communications with them. That should mean incoming and outgoing. If this isn't how Lemmy treats their block lists, that's kind of bizarre.
It's also not how I've seen things pan out in practice. Communities hosted on beehaw, for instance, are totally out of sync with the mirrors hosted on sites they've defederated from. Those sites do not appear to be getting updates from beehaw. There are a few breakthrough posts here and there, but from what I've seen they're few and far between, and it's possible they're arriving via third party.
I don't think the potluck analogy is a great one here, unfortunately. In the potluck, as described, all of the food gets placed in a central location, and people from all over can come and pick what they want from the table.
But there is no table here. There's no central location where instances go to pull content in from. Everything is passing back and forth from each other.
Instead, at this potluck, you carry your beans around with you all night, and sometimes people let you know that they'd like some beans. Thr fondu guy is also lugging his pot around, and sharing with people who ask.
But if you're not on speaking terms with the fondu guy, if he asks you for some beans, you're just going to say "no".
He can still get beans, though. And this is where I think things get hazy and difficult to interpret based on observed communities. Because if Iask you for some beans, and you give them to me, I can see that fondu guy doesn't have any, and I can share some of them with him.
He doesn't need to talk to you to get your beans. That doesn't mean you're actively handing them out to him, though. And he's at the mercy of other people who may be willing to share those beans.
And if everyone at the party decides they don't want to share with him?
Well, then he goes beanless, no matter how open he is to receiving beans.