The linked study appears to have focused solely on kids in primary school and the preliminary results are encouraging.
But as you know, there are other levels of education.
I'd like to see some additional studies that focus on students in middle and high schools.
At what point do infected kids become more infectious to others? That appears to be an important question, right? I mean...if we can get more studies suggesting that high school kids are similar to those in elementary school (in terms of the ability to transmit the virus), then yeah...why not reopen the schools?
But until then (and in light of the current surge of cases) it might be prudent to consider the safety of the teachers and staff.