The flags you mention are Venerated Symbols to these people in the school administration. The children were perhaps just acting out in a childish, uninhibited way, the sentiments of the adult American society in which they are situated.

We have similar issues in the UK; street level violence has ramped up to a huge extent and government, establishment and even the state-sponsored broadcast outlets are in collusion with winding back the clock to earlier days of repression of anything LGBTQ+

Things will get much, much worse before there is any chance of things getting better - if they ever do.

The forces of Reaction that have been entrenched and embedded within the Establishment is now awakening from its slumber and is literally on the march.

What foul Beast slouches towards Westminster (or Capitol Hill in the case of the US)?