Aren’t they just saying that rather than have a built in gps and program that will become obsolete they have you use your cellphones gps and app programming do the navigation and display it on the car screen. More and more cars are just providing a smart terminal that connects to the phone for music gps etc, without any built in programming. That allows you Replace the phone and get new capabilities. Also you can select the gps app you want and trust not the one built in.
I can’t imagine any phone that would be disconnected from the internet for an entire days drive or not have the capacity to download it all. But I guess a few carriers or cell phone are still like that.