Earlier quoted context omitted.
The author clearly thinks that the dash and and the nav are connected to the same thing in the back, when in reality the nav is a self contained unit that runs on the power from the car. That only happens when people frame the nav as the car.
CarPlay Ultra takes over the infotainment as well as the dash displays. The author is correct. In cars that support CarPlay Ultra, the dash screens are just additional infotainment screens that default to gauge display.
What I've been saying is that the infotainment is external to the car, not significantly more connected and integrated than the spare tire, and that everyone needs to understand that.