The program is very small because of the risk bringing a great NFO (that's how they get selected for NtP, it's about being a great officer, not potential to be a good stick) back for Not Observed TRACOM/FRS FITREPs while he retreads and his contemporaries are out getting good tickets on shore duty.
When he does get back to the Fleet, he's now a "senior" new guy pilot competing with other guys that have a complete tour under their belts as pilots.
The biggest risk is if he attrites from training, then you have just lost a great NFO for good as his career is pretty much ruined.
As for transitioning before you get into training, CNATRA has plenty of SNAs in the pipeline right now, they are still trying to work off an excess from last year. I'm not saying don't try, because you deinitely should, just don't get your hopes up too high.