This will require a confrontation. 

Prep yourself 

Get on committees

Run for School board

Find parent peers and allies

Define ALL terms

Demand Evidence to support the pedagogical reasons for proposed curricular changes

Ignoring it will not make it go away

Propose a free expression statement at your child's school

Go to the school counselors - They are important, impartial allies in protecting student mental health and an essential intermediary between faculty and administration (assuming they have been trained properly.)

Here are some articles and threads that may be helpful.

Remember that students comprise a captive audience or minors forced to attend due to compulsory attendance laws and, as such, deserve protection from adults' misuse of their access to them.

Books: David Moshman, Liberty and Learning.