Socially transitioning a child (ie what your school is doing) is not a neutral act.
Encouraging a child to keep secrets from their parents is the opposite of safeguarding.
OP, please think really carefully about what you are being asked to do here. If you are a parent, think about how you would feel if you found out your child was going by a different name at school and treated as a member of the opposite sex.
There are red flags all over this practice (unfortunately, I know it is increasingly common in schools). There are parents on this board who have found out their children have been socially transitioned without their knowledge.
I appreciate that you aren't SLT, but as a teacher you are in a position of responsibility, and this is a very concerning practice. Someone has to be questioning this.
Do you really, genuinely think that all of the children at your school would be in danger if their parents found out that their children were secretly trans?