And a school network manager should already be on top of such things and aware of several products that do just that.
Hell, even Windows Network Authentication (RADIUS etc.) can deny access if you don't have the latest patches, or an up-to-date antivirus, before you even get into products aimed at this.
Even previously, there are tons of freeware and other things that will warn about out-of-date software, including Windows patches, bad copies of Adobe Flash or Java, etc. and recommended upgrades. Any decent Enterprise Console antivirus can do the same. Any decent patching or software update system. Any device MDM solution.
Sure, it may not be "home" use, but that's hardly a groundbreaking insight to say "normal users need this too". Hell, I've seen any number of software installers that will refuse to run if certain components are out of date or insecure - some of them even for games!
And I speak as a school network manager myself.