I think pronoun/name changes should be respected as long as there's been a proper consultation with the child, parents and a medical professional. It doesn't impact on anyone else, other than that one child, but the school needs to explore whether the child is serious about transitioning and it isn't just an attention-seeking phase.
A unisex toilet needs to be made available for those who do not conform to the stereotypical norm. If those with disabilities can use a disabled toilet without complaining that they feel 'left out', and accept, it's a facility that has been set up so they feel more comfortable when changing/using the toilet, so should those who are transitioning. It's the only way in which girls can feel comfortable, and that child who is exploring another gender, can change in relative privacy while doing so. Nobody needs to be looking at the other gender's body parts while in school. It's, at the least uncomfortable, and at the worst, dangerous.
We need to have a philosophy in education where everyone is free to explore who they are, and carry out the necessary measures to do so. But no one else is to feel uncomfortable or at risk due to these explorations. So children who believe that they are the wrong gender can change their names, wear another uniform and such, but cannot do things which make other students feel uncomfortable, like having shared changing spaces.
No one should have to bow down to someone else.