They might if they were the kids of people working at the nursing home. I am not sure if this strategy will work either but I get it -- every infected and recovered individual is another control rod pushed into the out-of-control atomic pile.
The problem is that most of the people in the nursing home are the residents. If none of them get the disease, The R0 in the nursing home is still going to be well above one. The minute one person who is infected shows up at the nursing home, it races through the whole place.
Meanwhile, in the schools, the intention is to get the rate of kids that are immune as close to 100% as possible. That will be difficult without deliberately inoculating them, because they will develop herd immunity at about 66% in their population and it won't spread in that population anymore.
In the nuclear reactor analogy, it's as if you put in half the control rods, but only the ones on the left side of the reactor. That might make the left side strongly subcritical, but the right side might still be critical, even if with an even distribution of the same number of rods, the whole reactor would be subcritical.
This plan is not going to work and it will kill millions of people in Britain unless Chloroquine or something else ends up being a silver bullet for treatment.
