My guess is that
MA make most of their money (apart from islands/palaces/banks) from the players aspiring to be ubers. These peolpe probably deposit loads of cash in an attempt to reach that "uber" status, or get hold of that high end gear.
So ... my take on the event is that it's a tactic (ploy?) by
MA to say "look at what cool stuff you can do if you become an uber!"
Dez