Tl;dr:
Interrupted Program week + relocation --> permanude in Program free environment.
A derivative scenario in Naked in School universe that bothers me for a while. I don't feel competent to write it as stated here though. (I may or may not eventually arrive at a further derivative of this, but it's very low in the possible projects priority list, and that's under the unlikely assumption I write anything anywhere publishable ever at all.)
It starts rather cliche, we have one pov character, our typical for this: a grey mouse terminally shy and little reclusive bookworm girl with smallish tits who nevertheless is revealed to be pure ten beauty once stripped naked. Her parents had initially bought the bullshit about Program benefits and put her in the priority list, but she's not first week participant. Rather third or fourth week from Program introduction might work best, or respectively worst for this, as it is just about when I would expect the abusive aspects to peak. Early enough for novelty value of the whole thing still be fresh, but there's already enough familiarity with Program that put the initial guard down while everyone's still trying one-up-manship in just how far "reasonable requests" can possibly go, and similar.
Worse, it goes rather bad in her school overall from the get go, the public isn't nice to the participants and it seems the worst is enabled and encouraged by the management.
So, for your girl the first two days of it are just as traumatic as expected. She's probably not outright raped yet, but it seems coming. By Wednesday she's already in conflict, ruled guilty in avoiding some clearly unreasonable requests, probably by faculty no less, and informed she would have to repeat her week upon further infractions.
She is trying to adapt and probably still would become the typical slutified Program "success" especially as she has basically already resigned that she would be going naked for the second week anyway. She has examples that it does happen, and very graphgraphic examples of just how it ends up to be.
Her parents aren't blind and call bullshit on the whole thing. By Friday, she's brought over to a private school with strict uniform standards and no intention to even instate the NiS Program. She's chased down there by the regional (or whatever one-up) Program manager, accused of Program avoidance, scores her final infraction by arriving at the new school with clothes on, and while Program shouldn't have any power in that school, it ostensibly does over her while she's not finished with it yet, and the necessarily chaotic scene results in her being admitted to the new school... naked.
Come Monday she's introduced to her new class of uniformed peers nude, believing she's sentenced to remain so for no less than three weeks and possibly four, as she has to: finish her original interrupted naked week (no matter she only missed Friday and restarts on Monday), repeat that for scored infractions, and then yet another penalty week for attempted avoidance. Plus she's expected to score a new naked week in the new school with disregard to (or even because) it not participating in the Program, but that is allowed to be concurrent, given she dutifully checks her outreach goals.
This however is very different crowd, they could be rich entitled assholes by kind, but they at very least maintain facade of politeness, tolerance and acceptance, and they take the naked girl for what she is, a girl forced to go naked for whatever bullshit reasons. Their interest into detail of how it come to be may be superficial, but a naked girl is naturally fun to hang out with, and so she becomes an instant social starlet, rather inevitably.
She's adapting very well in the new environment, she's making fast friends and not being shy jumping participation into all kinds of ongoing projects and activities. Some possible future problems with the later she dismiss, thinking she will be allowed to dress before the drama club play takes stage or whatever similar. She has discovered freedom in her nudity, all the little perks like going through light warm rain without care and similar, thus her Program outreach goals score themselves, especially towards the end of her three weeks, as she provoke the new peers go skinny dipping and similar, and while she in practice has given up wearing clothes entirely, for now, she still believes.
As by now should be rather expected, come the Monday she try on the uniform of her new school for the first time, it turns out to also be last, as she is brought to principal's office and ordered to strip, for... uniform infraction. Respectively, it is explained to her that the school care nothing about the Program, they had come to her aid addressing her special needs and instated nudity as legal uniform standard and those are strict and she's bound by that: she's admitted as a nude student and will graduate as a nude student. Or, well, attending this school is a privilege and while they would be sad to see her go being all round A student and socially active (and a paying customer, I infer), that's what she have to do if she wants to wear clothes to school.
She calls her special Program manager, and get a confirmation, that's indeed the case, the school has no interaction with the Program at all. Further, thus the three weeks she's done aren't really counting, if she's changing schools again she will have to start that nude again, or still, but given how she's got nudity as her official school uniform, it's all good for now. The obvious choice is to remain naked and where she is.
This is a natural endpoint, but it would be fun if a plot hook or secondary conflict (that may or may not be a romance) would allow to explore what's basically a prolonged happy ending showing her final adjustment as a permanent nudist.
Maybe even picking up affiliate status with the Program derivative as Nude in Society participant allowing or even tasking her to be nude whenever technically possible, with or without goal to fight or fix the Program itself.
Maybe the news about nudity being legal uniform choice, even with the draconian all-or-nothing and permanent rules may incite one or more of her new classmates to make the jump too (no matter if out of pure thrill, in stated support to our heroine, or as a long standing wish come true).