set up != write software
From the little I played with Arduino's IoT platform, I honestly believe that if there is a compatible sensor that can detect vape smoke, almost anyone could get a simple version up and running. It was a very simple and largely automated setup if all you want is to get the sensor output to the portal and then link it to a UI element.
Of course gluing together this software is more complex than that, but it's no grand feat either.
Absolutely I am making a bunch of assumptions. Following the tried and true Keep It Simple Stupid approach. Because there is no indication given that any more complexity is required, and keeping complexity to a minimum is key to efficient development. If there was anything actually technically impressive (or at least technically impressive sounding) about what they did, I trust they would have mentioned it.
I do not claim to be amazing, and it's a simple fact that many basic examples/tutorials are named with hello world (and pretty easy to search for that way). A quick Google pulls up e.g. “Hello World!” of push notifications, Problems with simple "hello world" of ListView in Android
And of course I'm also explicitly using Hello World to reference the original comment
In all likelihood calling manufacturer's API to read the value then compare to a compile-time constant? It's a notification hello-world merged with display-a-list hello world and manufacturer's reading-sensor-values hello world. Yes I do think it's borderline trivial
Then why publish detection events like this? If they do start following up, all it does is warn perpetrators, and allow for fast iteration of anti-detection, to say nothing of other concerns people have mentioned (tripping other people's detectors etc.)
Unless there will be disciplinary follow-up ( -> no reason for this design), I only see this going the way of de-facto scoreboards among kids.
Going by the phrasing I'd say educated guess. I for one agree, it sounds like a massive liability when you have e.g. data protection laws to think about