As ammending 1001.42 §8, Paragragh (c)3: "Classroom instruction by school personnel or third parties on sexual orientation or gender identity may not occur in kindergarten through grade 3 or in a manner that is not age-appropriate or developmentally appropriate for students in accordance with state standards."

This seems to pretty straightforwardly say that schools can't talk about the existence of gay or transgender people in K-3, or ever if it's not "age appropriate or developmentally appropriate"... according to standards that the state gets to set.

Heterosexuality and traditional male/female rolls are also sexual orientations and gender identities, are they not?

You can’t logically ignore half the reality of a statement to claim victimhood.

That's partly the issue of concern, isn't it? Giving children the idea that if they don't fulfil a traditional male or female role, then they must be some alternative gender identity.

Many people don't agree with this stance, both from a conceptual point of view, and that in practice it may lead impressionable children to want to modify their bodies to fit some idea of gender identity they've had instilled.