When I looked at server/chat-commands.js in the code, I found that when a user becomes unbanned, they don't receive a popup saying that they were unbanned, and I think that it wasn't implemented because it isn't possible for a user to be in the room they were banned in. Like mutes, if a user isn't in a room when they become unmuted, they don't receive a message. So I think that users should be notified of unbans, because they would have to attempt to join the room to check if they were unbanned, though I'm not sure if it should only be implemented for being unbanned by staff or also for ban expiration. Same could be done for unblacklists. Maybe global unbans too, but it would require reaching out to the user outside of PS.