Rc,
Boys need to come home earlier from israel.
Mathematically, that should help.
RYs need to own up to this crisis by imposing takanos
You were right that takanos are difficult to implement. There’s enough negativity towards programs that are purely voluntary; imagine the backlash if R”Y tried to impose their will by force!
that mothers of boys respond in a reasonable amount of time.
If the lack of timely response is causing the boys to put their dating on hold, then you’re right to associate it with the disparity in numbers. If, however, there is no immediate answer because the boy is already busy with someone else, I don’t see what there is to do about it – there’s no point in a boy (or his mother) giving a definite “no” if there is a possibility that at some point he’ll want to meet her.
There is a way to close the gap that the R”Y of some yeshivos could implement – the post E.Y. yeshivos could limit acceptance to bochurim under a certain age, which would “force” them to return from E.Y. sooner. This is actually implementable, but many factors would have to go into such a decision.