CarPlay already doing navigation-in-the-instrument-cluster part in my car. It is much worse than built-in navigation integration. It is just a stack of direction arrows. Now Playing works perfectly fine via regular BT over the last 10+ years. Any rental car I had will show it in the instrument cluster.
Interesting, you did not mention speed or gas/charge gauge as the main things to look at. I for one will not trust apple to display my current speed (see mockups shared above). I've seen plenty of cases when CarPlay will pretend that it is working (play music, show message popups) but totally forgets to update navigation position since 10 miles ago.