Its part of the "text book" politically correct stuff.....
You know the stuff that sounds fantastic on paper but is ridiculously silly when applied to real life.
Calling a child anything but what they are is considered demeaning and/or inappropriate. Much like saying I am a girl. I am not a girl, I am a woman.

Whatever.... gal, lady, woman, girl, female, lassie.... it's all silly if you ask me....
The one thing I learned in college is whoever came up with some of this stuff has obviously never actually worked with children. or kids.