Rebbitzen etc, the preventions you mention in your last post are all within their means to accomplish reasonably quickly. Getting everyone in their classes married is beyond their control. Chesed is to try to help others, whether that help will actually take away the tzara is sometimes beyond us. yes, the happily engaged couple can and perhaps should be encouraged to suggest a shidduch, but it doesn’t mean it will work out. We as a couple over the years have set up a few people, nothing came of any of them. I know another couple who have made several successful shidduchim. Our failure rate and our friends’ success rate has nothing to with degrees of selfishness or caring for others.
I think it is more the norm for newly engaged couples to want to share their joy than hide in their bubble. Many couples do try to set up their friends. Among my school friends, there was couple A who set up couple B who set up couple C, all the chossonim were friends from the same yeshiva. (Couple C tried to set me up with one more from that yeshiva, and I was sure by the natural order of things we would become couple D, but surprise, it was not matim…and I only got married many years later).
It took my HS class about 15 years until we were all married, and about 6 years for most to be married. I would not consider it a chessed for anyone to have waited that long-even the 6 years- it would have been more like a churban. It would not have helped anyway. Maybe it would have even discouraged some to date- why bother if they can’t get married until everyone else is? If we would implement your idea, then no one would be able to deny or question whether there was a shidduch crisis.