This is a mess... Why not test the sewage to see if there are positives and then test everyone including kids if there are positives? Teachers and staff are a small proportion of a school population and transmission is more likely between students who will be in closer contact so this program doesn't make much sense unless everyone is tested or maybe some kind of random spot testing including students. Of course, it's easier for the organization to target the employees. There is a form of union within ESF, I guess they could try to pressure management, if teachers band together, it could get a lot messier.
It would also be important to specify what will happen in case of a positive test. It's been pointed out that a whole hall of students were sent to quarantine even though they were all masked and distanced. What happens if there's a positive in a primary school? Teachers are parents too so what happens to their families if they are sent to quarantine because they are deemed a close contact.
Instead of announcing a policy and scrambling to figure out the details, maybe the opposite should be done. Guess it's par for the course in dealing with the virus... Trial by error.