None of these places have the case rates we have, nor the focus on individual rights versus social responsibility that we have here. I do not know what the risk is here, but using other countries as models when our country has continually been an outlier seems overly optimistic to me, especially given that increased testing is not behind the rise we are seeing right now. You claim it is less risky for teachers to be working now than other essential workers, based on what? Many changes in work place practices have occurred to protect other essential workers; I am working every day and masks are mandatory, there are no f2f meetings, we are tested every week, all air is single pass, there is no recirculated air in the facility and 90% of the staff works from home. I also believe children are at higher risk for becoming infected than someone getting hit by lightning. The odds of being struck by lightning in a given year is ~1/1,222,000.
Much in the article below and others I've read support much of what you say, but as they point out data is scarce and it is situation dependent. What I have seen proposed for some schools has been essentially nothing - no masks, no social distancing between students, no barriers, and we in no way have the virus under any sort of control. I just think there is a lot more risk than you are giving credit for if for no other reason than the scarcity of data.
www.sciencemag.org