Should the instances that responded to you be refederrated? I’m pretty sure I saw some of them on lemmy.world’s block list. I think it would be sad for these small servers to not realize they are, in fact, not connected to the greater fediverse. On the other hand, if you’re an admin, and you don’t know what you’re doing to the point of not knowing your server was infected by hundreds of thousands of bots, maybe it’s too dangerous to refed.