They'll have to. 315 schools apparently currently have had confirmed cases of covid19 within their populations, and it's rising dramatically. It's just not sustainable like this, and as cases rise, it'll become even less so.
We desperately needed better planning by government for this. This is exactly the situation that a lot of us have been worrying about for weeks now.
If they'd sorted out combinations of distanced learning, mixed with smaller classes or regular but part-time learning (by using other public buildings/building extra classrooms over the summer/offering well-paid jobs teaching smaller, distanced classes to the large number of qualified teachers who have quit the profession over the years, then the economy could keep going more easily and fewer people would be at risk.
It's such an unnecessary situation.