This is accurate. Very similar to the Navy too.
Assume roughly 500 slots a FY for USNA Mids, ~500 for (NROTC, OC's, and STA21 [who are not previously designated]) then the leftover slots are carried over to OCS. Unfortunately for you OCS bound people, that is not many! Good Luck!
First off, thanks debbie downer!
Second, I would doubt the Naval Academy sends almost half its graduating class to be pilots. They have surface and submarine missions that need leaders, too.