Marisa,
You are right.
The deadline is not "hard" in the sense that there would be no penalties or anything like that. It is for the participants to push themselves to finish the 30 in time, so that they can focus on promotion, along with everyone else.
Everyone who has not finished their 30 hubs can finish during this week, so that they can get onto the promo train, even as it is still picking speed. After that, they might find difficult to keep up with the momentum.
Obviously, participants with 30 finished hubs will be in a much better position to benefit from the promo phase.
I am through with my 30. 