Yeah and that's a low possibility, when you do this, they will get your ip address from your unban appeal, then they will put the ip address into database, then they will figure out that you're banned.
Now you will quickly say in an impatient way "use vpn ! ! !" okay, use vpn, show yourself like uhm. from america, then they will ask about your old account name, and then search for it from server logs to see the days when you joined the forum. Then they will figure out that it's actually a newly created account. You can't use that method against everybody else you bump into.