With iPhone 15, they also introduced the ability to call for roadside assistance from AAA via satellite too. (I’m not sure if this is also available on 14 now or not.)
> If your missing device can’t connect to the internet or has little to no battery life, the Find My app can still help you track it down using the Find My network — hundreds of millions of iPhone, iPad, and Mac devices around the world.
So this isn't going to help you in the wilderness.
The passage you quoted is talking about the iDevice-to-iDevice communication that can happen behind the scenes allowing you to find a lost phone in the wilderness if someone else so happens to walk by the phone.