I think the law is going to be tested in future unfortunately with maybe requests schools separate boys and girls.
I find some arguments about gender segregation and not through personal choice similar to separate but equal in historical rulings within the US.
Through long hard battles through the centuries Britain has moved away from patriarchal systems and we need to continue that struggle.
I think free will is at the heart of this and I am yet to be assured people practise religions purely out of choice and Islam does not seem a religion which offers faith/non faith choice to it's young people. I think a test of the strength of faith is its observance without coercion.
The oxymoron of Islamic feminism I think can be jarring and I suspect many (not all) young Muslim women are subjecting themselves to restriction in order to avoid ostracism and abuse.
Figures on Muslim apostates are hard to gather but it is significant. The removal of faith though has social damage akin to leaving a cult so we have to be minded how difficult it is for people of devout parentage to explore atheism and liberal values. I would fear any teacher supporting critical examination of faith may be hounded out of a job.
Tolerance does not mean acceptance either. We tolerate other people's religion but that does not mean we accept the ideology or a way of life associated with it I suppose this is another argument for secularisation of schools in that the school is not beholden to any one groups religious viewpoints
This is also about respect which is fundamental to a working society. We respect people being able to practise a faith in private so people should respect a school's decision to have secular values. A court has ruled on the validity of not offering prayer time so we have to respect the rule of law.
Maybe it comes as a surprise to some who immigrate that their host culture is different but it shouldn't. I think this is why explaining British values e.g. democracy is important e.g. the law overides and religious law that exists independent of it