The paranoiacs are demonstrating their true intent of imposing their belief system on others, which is in violation of their own policy:

The Board will permit the introduction and proper educational use of controversial issues provided that their use in the instructional program:

...does not tend to indoctrinate or persuade students to a particular point of view;

If parents don't like something, they can take advantage of this part of the policy and simply block their kids from the "offending" material:

The Board recognizes that a course of study or certain instructional materials may contain content and/or activities that some parents find objectionable. If after careful, personal review of the program lessons and/or materials, a parent indicates to the school that either content or activities conflicts with his/her religious beliefs or value system, the school will honor a written request for his/her child to be excused from particular classes for specified reasons.

https://go.boarddocs.com/wi/mnsd/Board.nsf/goto?open&id=BGEQ8S681948