The burden of proof is on the affirmative.Infact they do.
They are out of step with the majority of schools nationwide, I suspect. And probably, with the majority of schools in Mississippi. That's a good indicator that they are not vital and current.Maybe they are vital and current.
My daughter's school requires APPROPRIATE formal attire. The dresses and/or formalwear that the students wear must fit the same requirements of clothing on a normal school day. that means no bare midriffs, shoulders, etc.
I have considerably more concern about girls EXPOSING THEMSELVES at prom than I do about a girl in a tux. A tux would certainly be more modest than the average prom gown.
Have you considered that?
The goal of prom is to reinforce gender roles? Wow. I'm guessing you don't have a lot of interaction with teenagers.