A 3 month mandatory waiting period after an EB has been annulled would make it a little more of an event, both in my opinion and many others that are a little let down by the system.

Most just EB for the free teleport and clothes, then forget about it. This is part of the reason why the events also are no longer really invitationals, aside from very small groups. Everyone used to go to one if they heard about it, because it was new. If there was a sort of limit on how often it could happen, it would make them somewhat more interesting and inherently valuable.