That's exactly what it is.Maybe it'd be better as a "carOS" which would run without an iPhone.

Apple’s fancy new CarPlay will only work wirelessly
And many other notes about the future of Apple’s ideas for the car.

"So, for next-gen CarPlay, Apple’s split things into what it calls “layers,” some of which run on your iPhone while others run locally on the car so they don’t break if your phone disconnects."
There are so many articles about NG CarPlay not releasing on time. I wish there were more articles, like the one above, that explain what it actually is. It would certainly cut down on noise in threads like this one.