Clearly it must be, as you failed to give that answer in the numerous replies that you made to me in this thread. The answer for a 12 rider format as confirmed by 'Main Man' is due to lack of rider availability, otherwise I'm assuming it would be a 16 rider format.
I do find it hard to believe there are only 10 riders from this Country that want to/can ride in the NYC, but if that's the official reason, then fair enough and I wish them all the success in running the event.