My OSO gave me the scoop.
After your flight physical at Pensacola, your application bounces from one place to another until the medical portion lands at the final stage, NOMI. Apparently there is only one individual who clears all of the air contract medical applications. He is very meticulous, very thorough and as a result the process is not quick. So all these applications are caught at this one bottle neck. Obviously if the medical is not cleared at every stage, the air contract is not valid.
I am unsure exactly how it works, but the way it was explained to me is; the people who have already signed the contract for OCC-200 can roll the dice, switch to a ground contract and go through OCC and hope that in the 10 week period they become cleared for Air and switch before they take their commission. If it doesn't happen, they can take the commission as Ground, then switch to Air in TBS (if and when they're cleared medical), but it is more difficult to do. The down side to this is if you sign both an air and ground contract and your medical is rejected, a ground MOS you will get.
If you've already signed an Air Contract for OCC-200 but been pushed back, the OSO can hold your contract and you can ship in May for 201. If you're planning on going in 201 anyway, get everything done sooner than later to insure that your medical application can go through before you ship.
Keep in mind, I'm not an expert at this particular subject, so if it's not 100% accurate, I apologize. This was all explained to me by my OSO. So, before you make any big decision double check with your OSO. But I didn't need to tell you that.