I think I get it now and I think it's probably not about the stresses of closing school: I think it may actually be a calculated gamble that what you want is th

I think I get it now and I think it's probably not about the stresses of closing school: I think it may actually be a calculated gamble that what you want is the low-risk population widely exposed first, falling ill at a rate just below the level at which you can treat people. If that rate threatens to climb, then maybe they close the schools and try to slow the rate. Otherwise the at-capacity wave is moving people from the "not immune potential vulnerable & vector" population into the "immune and not a vector" population. If that's the case... it seems like it heavily relies on timing, good data & models, and more precisely timed and effective social cooperation, and I'm not sure I'd want to bet on having all those pieces in place, but it is interesting.