Pba,
You acknowledge that (1) there are more 9th graders than 12th graders.
I assume (correct me if I’m wrong) that you would extend that to say that (2) there are fewer 12th grade boys than there are 9th grade girls, and that you would also agree that (3) the tendency is for the 12th grade buys to marry the 9th grade girls (eventually).
You started this thread assuming two flaws in the application of these facts to the shidduch crises. The first, if point (2) is conceded, would have to be retracted altogether. The second would only be true if it were reasonable to assume that there are more girls leaving the conventional shidduch pool than boys. Anecdotal evidence suggests the opposite, and it’s a waste of time, money, and energy to try to prove the obvious with a controlled study.