I am very curious to see how many people take advantage of this policy as I believe the science is pretty sound (and has great evidence of over 175 million people in the US have received the vaccine with a tiny percentage having negative effects). If it's a low number and still allows for herd immunity, I think it will be fine. If not, then we will have some problems.
In the meantime, a few teachers are suing the DOE over the vaccine mandate. I doubt it will go very far considering what the Biden administration is doing federally.