Well, look at it THIS way....
They could do multiple things to adjust the live balance they're seeking from the experience they studied from our beta playing. They don't have it now, it seems. If they don't like the balance of event difficulty, or rewards breadth or depth, they can move the knobs and dials a few ways.
1) They could leave the event exactly delivering the previous quantity of workers and from the same sources, and LOWER the reward structure so the buildings are not as powerful or we can get as many from the range of experiences (paying, non-paying) people had.
That's not an result I think they want. They want to show a good game turnout in live for their financial goals and "mother Earth" cause. So they do know from beta that keeping the buildings sized the way they are AND rewarding the way they are, has value.
2) They could (and did) change the amount of event currency they're offering, and keep the buildings the way they are. This re-balances these 2 from what they learned in beta.
So far, for beta players, it's AFTER our playing and rewarding - and this is preferable (for a number of reasons). If you have to ask why, think harder about why first, then you'll get an epiphany...