A little history -
When CNATRA went to MPTS, there was a difficult transition. It was hard for IPs and commands to forget the "old" rules - pre-MPTS (TA Manual) and accept the MPTS rules. Under the "old" rules, there was a minimum 35 NSS to select/wing. Under MPTS, this rule was dropped. Primary was put under MPTS first, so no one really noticed that everyone who finished Primary selected and went on to advanced. No one really noticed because all the sub-35 NSS studs went to helos, and who cares about the helo training pipeline. As long as Tacair is getting their studs, everyone is happy.
However, when the advanced squadrons converted to MPTS, there was a shock in the training command that students with a sub-35 NSS could end up as winged aviators.
However, there was a huge misunderstanding what it all meant. MPTS attempts to set a standard to be an aviator, affectionally called MIF. If you meet MIF, then you meet the standard and you should be an aviator, regardless of NSS. That's because NSS just ranks everyone that successfully completes. Getting a 20 NSS doesn't mean you shouldn't be winged. It just means you're at the bottom of your class. Hey, somebody has to be there.
Now, there was concern that the training command was passing on trash and needed to screen selectors/wingers. Hence the instruction that brought in the "Command Screen." This instruction was post MPTS and was meant to ensure that the bottom of the class is in fact qualified to be a Naval aviator.
So, you can have a sub-35 NSS and select/get winged. Many have. Many will. And they should be.
To the question of 3 strikes and your out. That, as well, went by the wayside with MPTS. Because of the nature of how unsats are awarded under MPTS, it would be unrealistic and counterproductive to flush every student that get 3 unsats. Unsats are not downs. Never were and never should be considered one. Dropping the 3 strike rule had nothing to do with needing more bodies in the fleet. Again, because of the confusion during the transition from the "old" system to MPTS, there may have been Primary squadrons under MPTS still using the 3 strike rule, even though they were wrong to do it.