It's a super useful safety and accountability feature. Some people are uncomfortable that their coworkers can see they're *still* in the airport bathroom, which is fine and why it's voluntary. you open the find my app, select who you want to share and when. you can share for an hour while you're all trying to get somewhere (like in this case), or for a day if you're flying in to/from multiple locations to make sure nobody misses their flight etc.

In this case it quickly let people know this guy is not coming to happy hour, he's at the hospital, and allowed for a faster response notifying people vs finding out the next day or whenever the hospital decided to try figuring out who this is and who to contact.