I just wrote a massive post and lost it due to a page reload but you said it in fewer words anyway!
Absences are categorised as ‘Authorised’ and ‘Unauthorised’, so surely schools could just exclude authorised absences from their prom eligibility calculations (rather than use overall attendance percentages)? Students on reduced timetables (like the young carer in the article) should similarly have their prom eligibility attendance individually calculated according to whatever ‘reasonable adaptions’ were agreed.
My DD’s attendance was 20% the year she had chemo - I probably would’ve gone Full Compo Face in the local paper if she were excluded from fun school events after reaching remission due to her overall attendance record! Thankfully her school were not that heartless (and she’ll probably never have more than 94% attendance due to multiple half day absences for hospital appointments).
Fair enough excluding persistently extremely poorly behaved students (violence, drug possession etc) from prom/disco, it reflects the same sort of consequence that happens to adults who behave similarly (eg getting kicked out of nightclubs/barred from multiple pubs under the Pub Watch scheme) and the exclusion is motivated by the need to keep other attendees safe.
But being excluded due to circumstances caused by illness, SEN or a difficult home situation (eg not always having a PE kit because your homeless family is squeezed into one hotel room with no access to laundry facilities) is just needlessly cruel and does nothing to improve the prom experience for the kids with exemplary records.
I generally support schools that have a clear merit/demerit system but is has to be fairly and consistently applied and the school has to dedicate resources to mitigating any circumstances that unfairly penalise students who are trying their best in challenging circumstances, otherwise the sanctioned kids end up demoralised and demotivated and that leads to even poorer attendance (and in some cases, even more disruptive behaviour).
Cuts to public services/post covid difficulties/CoL have dumped a lot of additional shit on the doorsteps of schools and some schools are doing much better at handling those challenges than others.
Teens who forget to bring things in or who are absent due to circumstances beyond their control shouldn’t be lumped in with the small minority of teens that really do put the safety and wellbeing of the majority of students (and staff!) at risk.