$$$$$$$ it costs a lot more of it to can someone AFTER they've completed primary. That's not saying that one should make coasting by plan A, that's never a good plan. I suspect that the measures being taken at API are an effort to refine the process so that if the Navy needs X pilots, it sends X pilots to primary. Reasonable man theory says you probably ought to send X+Y, knowing you'll can Y and still be left with the best people to fill the requirement.
That's probably the biggest reason why we've seen poorer performances in Adv and the FRS. Also why its become so damned difficult to get rid of someone the further they get along in the pipeline, no matter how badly it should happen.