I don't think the responsibility is on the children for assuming they have privacy on a school-issued device; surveillance often happens without transparency, and it's reasonable to not expect words like "gay" or "trans" in your writing to automatically be flagged and sent to administrators.

While it's great to educate people on the threats and the ways to mitigate them as individuals, there are policy choices being made here that need to change and the focus should be on how we can achieve that.