I definitely agree. I can see where boys would give him a hard time if he's into girl's things and presents himself as a girl. But trying to segregate him into a girls only environment could backfire. I've known of boys who've had big sisters, who went through similar stages, and then ended up perfectly "normal." Once the hormones really started kicking in, they looked back and laughed about it. But to label them as "transgender" at the time, and then expect them to live that way from that point forward, that's a parenting issue. This type of issue has been going on for a long time, so it's not like a parent couldn't ask the pediatrician about it, pick up a book, or surf the web and figure it out.
If the mother was really looking out for her son's best interests, it seems like the boy would be visiting with a therapist and not being placed in the center of a controversy. People don't like having things forced upon them. And I know I wouldn't want to be in that boy's shoes (I'd look terrible in women's strappy boots) if I had to go into that environment because my mom thew a hissy fit.