Air quality improvements are strictly temporary if the factories go back to full production under the same techniques. Which they will unless this becomes a full blown depression, I hope not. To sustain that improvement we have to get better at making things more efficiently.
I disagree completely about the kids. Mine are homeschooled, and I think there is strong evidence that large groups of same age children encourages learning poor social behaviour, bullying, etc. The need to be in mixed age environments, to see and learn from adults who have a broader perspective and learn how to interact in positive ways. All the kids spending time with their parents right now is a huge positive of this mess in my view.
It definitely pushes remote work closer to the norm. Some will love it and keep doing it, others will hate it and push back. But everyone who starts doing that regularly is a real reduction in pollution and traffic from reduced car trips.
If this lasts much longer, I think social norms will move away from handshakes, just get rid of them already. Maybe we can all be Japenese and bow from a distance, or go Vulcan with the live long and prosper split fingers wave.