> But I mostly got stuck in privacy concerns. I'm not sure it's a valuable public service to let people know that, for example, someone had a heart attack a few blocks over.

In the moment, notifying people who know CPR and may be nearby and able to get to a nearby location and start CPR before emergency services arrives is the base of PulsePoint [1], which seems like a useful public service.

As a digest, yeah, I don't think any usefulness outweighs the invasion of privacy. Maybe just a count of health emergencies responded to for observing trends.

[1] https://www.pulsepoint.org/