All other public schools, you mean. Private schools can teach whatever they choose to teach, provided they meet the minimum licensing requirements for private schools. The article does not state whether this particular school meets those requirements, but fails to address the topic one way or the other.
sorry, but you are wrong....and I am extremely familiar with private schools. All education facilities, in this nation, have oversight by the local, state, feds. Private schools are not exempt, yet there is some exemptions for private verses public, though the exemptions are not extreme. This school is an extremist school and this school does not want oversight, but by law, this school will be overseen or closed.