Why is multiple county and school district-wide segregation policies "personal racism" but as soon as it goes to a university it becomes "institutional"?
Your story, by contrast, is about a school enforcing honor codes in a discriminatory way. That’s something schools face tremendous Title VI liability over. It’s completely different.
... specifically because their school districts specifically voted to drop school sponsorship of proms because of desegregation, to legally insulate the schools and districts. Rather ignoring the concept of cause and effect.
Again, the numbers spoke to the truth of the matter. White people were reported and expelled at a rate that was so much lower than their non-white and international peers that it defied credulity. Men were also accused and expelled at a rate far higher than women were - something tells me you won’t push back against that.
The school didn’t end an over century-old practice that was a major point of pride for them because of vibes. It ended because it was harming only certain groups and was not effective at curtailing cheating.