Here's the thing, and an article was already written expressing this. No one knows what this event actually, is/will entail, or what, if any, nanana-booboo collectors pop they will give.
The article writer says dropping a legendary there would be a mistake. The raging and potential quits would be quite a lot.
I kinda agree. But they need something. Ticket sales, people commuting and booking hotels and whatnot...
It cannot be like that other lame thing they did, that nobody even wants to remember cause it was so pointless.
My idea? Shinies. Getting your ticket down there should reward you with...all three shiny kanto starters. Or...your choice of ONE johto starter...or pikachu (I would save this last one for the Japan event, personally). Something like that.
And the event guys need to keep those stops lured. The WHOLE time. We are going to be paying the money. That expense should be pissing pennies to them.