Sounds to me like some are misunderstanding that "trans boys and men" are going to have been born female, and therefore, likely to have periods. They aren't saying the opposite: that people born males will have periods.
Maybe some don't like the fact that schools have to deal with having transsexual students and teachers in the first place- but if it's a fact that they do- then it's only logical it has to be addressed now and then.
I just don't get why this issue lights such a fire under some people's asses. WHY do people care so much what gender another person wishes to live their life/ be recognized as?
Most things I like to look at from a logic standpoint, not emotion that doesn't actually remedy anything. (And too many issues are emotion-driven and practically logic-devoid.)
Getting bent out of shape over the gender-identity of other people is completely illogical. There's no 'solution' to it other than just leave other people be, and stop fretting over them. There's no 'slippery slope' to leaving people alone to be who they are. It's not affecting you or your kids. Other rational adults must sometimes address the fact that transgendered people are a reality, and discuss them in guidelines, rules, laws, whatever. The whole, 'who uses what bathroom/shower/gym whatever' and that whole line of bunk is BEYOND idiotic.