I think there would be outrage if

any (non-state) Christian based school here suddenly required all female staff to wear a cross - even a discreet cross. It would make no difference even if all the female staff were Christians. If any of them objected to the requirement to do so then I have no doubt at all that the media would be instantly on their side. Politicians would be speaking out in their favour. There would be complaints about the way in which people were being forced to do something of a religious nature. Any government funding or outside sponsorship to the school would probably be instantly suspended pending an inquiry and a resolution of the issue. The issue would be resolved without going to court. The school would simply back down and accept that they could not make such a requirement a condition of employment. People would say that requirements with respect to what you wear can only go so far.
My father always wore a shirt with collar and tie with good trousers to school - and, except in very hot weather, his suit jacket as well. Things have changed since he retired but many non-government schools still require male staff to wear a collar and tie style of dress at least part of the time. They do not allow jeans and t-shirts. Why should they? They do not allow the students to dress that way. 
My mother always wore skirts. She never wore trousers to school. I did wear trousers but my teaching position was in a school where most of the children were in wheelchairs. All the staff did.  We often sat on the floor with one of them cradled in our arms as we encouraged them to do something. I did not wear jeans. 
It seems the situation is a little more complicated when it comes to the wearing of a head covering if you work in an Islamic school. We have an Islamic school in this state. The female students who attend it are required to wear the hijab. It is part of the school uniform.
Not all teachers at the school are Muslim. It is unlikely the school could find that many Muslim teachers to work there. There is a requirement for women teachers to "dress modestly". I have no problem with that if it means clothing appropriate for teaching in. But the governing board of the school has now said that all female staff must wear a head covering. They have warned that those female staff who do not will be sacked. It was not an original condition of their employment. The new and more conservative governing body has decided it will be a requirement. It is not the policy of the peak Islamic body in Australia.
As I understand it, someone please correct me if I am wrong, there is no religious requirement for a Muslim woman to wear the hijab. It is, at least in this country, a matter of personal choice - or it should be. I have little doubt that there are Muslim women who wear it because the males in their lives demand it. 
Dictating that anyone must wear a religious symbol belonging to another group seems very wrong to me. What is even more worrying is that this demand is being made in a country which does not, as a whole, accept that this is the normal dress code for the majority of the population. More worryingly still, rather than come out and say that such demands are not acceptable, those who have spoken publicly are choosing their words with extreme care. They are clearly worried about upsetting this tiny conservative group - far more so than they would be about upsetting other tiny conservative groups. 
Before writing this I spoke to the mother of two children who attend the school. The mother wears the hijab, indeed she always wears long sleeves and her hems reach to the top of her shoes. It is, she says, her choice. And that is what she said about the requirement for female staff to wear a head covering, "It should be their choice. I wouldn't wear a crucifix so why should they cover their hair?"
The Equal Opportunity Commissioner said it is a "grey area of the law". It seems to me it is another example of the unintended consequences of "ant-discrimination" legislation having the opposite effect from what was intended.