They are alowing 2 events for everyone so they will have a chance to use up (mostly) 1 set of new tires.
They never factor that most all of us have tires in various stages of use. I have my best set to race on. I have another set for practice. I have a 3rd set for DE's and fun rides. I even have a set of full tread rains (16").
I'll be willing to sell the 16" ones.