And why do you need that?
Because otherwise, people get to pretend that they've never been banned. We already have this information from the ban appeals section, but people change their names to obfuscate their history (which in some cases doesn't remain only their history). Making ban information available also makes being banned much more of a punishment, since that player will carry with them evidence of wrongdoing. The current system doesn't discourage cheating as much as it discourages being banned. Once a player is unbanned, who cares? They can just cheat until they're caught again, and only people who actually pay attention and remember might know better. The highest punishment in the server should at least have a few lasting effects.
Sometimes,players are getting wrongfully banned by AC (bug). You can't blame them for something they didn't do.
Fine, then remove those wrong bans from the history. I do think that some bans shouldn't necessarily be in the history forever, such as bans for non-cheating offenses.
It wouldn't be helpful in gameplay. Also adding many things means adding more bugs. Just look at UIF server, it lags like hell.
Couldn't you argue that people cheating, getting banned, then getting unbanned with no long-term consequences to discourage them (and others watching) from cheating is detrimental to gameplay? I can't see this adding much bug-wise or causing lag, particularly if it's in the CP.