This was originally going to be a quick reply to a comment, but I might as well go into more detail and put it where more people will see it.
I figure there are three basic scenarios for nudity in the NWO setting, not counting oddball stuff losing your clothes while skinny dipping or registering by accident somehow. But first let me back up a step and talk about the legal framework. The main plank of it is of course so-called Permanently Naked status. You can either sign up for it, or it can be imposed as a punishment for a crime. (Then there’s Permanently Topless and Bottomless, which are an alternative voluntary status and punishment, respectively.) But also parents and schools can impose nudity on their children and students. And this is more flexible. It doesn’t last any specific length of time and they can make up whatever rules they want. Also note that this includes adult dependents and students in any type of school, so feel free to assume all characters are 18+.
OK so #1 you’ve got voluntary nudity, where someone registers on their own. This also includes some cases under parental or school authority where they ask to be naked or willingly sign up for a class that requires nudity etc. #2 is nudity as a punishment, either for a crime as above, or when parents and schools use it in lieu of the more traditional grounding or detention. In any of these cases it’s intended to be embarrassing.
Finally #3 is nudity that isn’t voluntary, but isn’t meant as a punishment either. It would include nudist parents who want the whole family to be naked, or schools that believe it’s beneficial (either in general or in specific case) for students to experience nudity. In these cases it’s not intended to be a method of humiliation or presented as a bad thing at all. Even though they don’t have a choice, that could have a big effect on how someone experiences it. Although, of course they might still be embarrassed, especially the the first few times they have to do it. The version of this I’ve referred to most often Body Comfort Week, where a school requires all students spend a week naked both in an out of school, probably once a year. As the name implies it’s meant to encourage a healthy body image. It’s probably not very widespread, but it has its proponents and it wouldn’t be shocking or anything to find a school with that policy. Schools that use nudity as a punishment are less likely to do it of course, as the two policies would be working at cross purposes.
So anyway, to directly answer the question I got, this post here is an example of something like that. Evidently they have a more flexible system where students have to spend a few days naked per year (probably one a semester or something) but they can pick the days. I’m inclined to think having everyone naked at once is a better idea if the goal is to get everybody comfortable with it. But maybe this school has a different purpose in mind, it could be intended more as a challenge to build confidence or something. So that’s the third kind of nudity, it’s probably the least common (in my captions anyway) but I’m sure it will continue to come up from time to time.