I still think an outright ban on facial hair would likely fail First Amendment scrutiny, largely for the possible array of religious and social reasons for facial hair. Schools are given wide latitude to create and enforce dress codes, but they cannot ban whatever they want. See Tinker v. Des Moines. Still, someone would have to care enough to challenge it.

If my high school had that rule, I would have been in trouble basically every day. I shaved maybe once or twice a week, and looked like my usual scruffy hobo self most of the rest of the time.