The whole point of public education is that we work from and toward a common denominator, what we believe is important for everybody to know and appreciate. Educators are the only ones in a position to make that call - even if individual parents disagree with them sometimes. If parents want more personalized involvement, then they need to attend private or home school.
I also think it would be a major step backward for nonbinary individuals and same sex couples to be forced into invisibility again. We really need to stop being so afraid of these differences.