When you are close to them and connected to them, the map will show your own location not the AirPods.
This explains why the AirPods tracked the authors own location at times. Possibly also why the map showed the boys location. He was using Bluetooth so his phone was actively listening, and actively connected to the internet and due to this, the boys iPhone was quick to post it’s location when it heard the authors AirPods. Where as other people in the museum was not using their iPhones so their phones would not be actively listening or if they where would not upload the position in real-time.
If it means even a slight chance of attracting unfounded vigilantism, mandatory participation in a poorly understood surveillance network seems like a pretty big downside associated with using an iphone.