Though I wouldn’t consider a 12% gender discrepancy anything remotely resembling reality)
For birth rates? Of course not. For numbers entering shidduchim? It’s probably in the ballpark.
It seems you missed AZ’s post, in which he claims that 1) and 2) are both true. That my hunch as well; Dr. Halpert assumes that the gap is wider than in the past, but I didn’t notice if he addresses population.
I keep on evading your hypothetical question because it denies a mathematical truism. If I told you that 2+2 does not equal 4, would you consider that it equals 5? That’s kind of how I view your question.
Could changes in the way we date improve the shidduch system? That’s a better question, and I think the answer is yes. If people would make better choices, there would be more marriages; the imbalance doesn’t explain the single older men. But making better choices (not age related) can’t address the imbalance of having more females in shidduchim than males.