Google has reportedly developed an "Assistant Driving Mode", which will supplant Android Auto for Phone Screens with the introduction of the major 12 OS upgrade. Therefore, users with mobile devices that install this OS version will only ever find Auto on their cars' display going forward.
https://www.notebookcheck.net/Android-12-is-now-slated-to-replace-Auto-for-Phone-Screens-with-the-Google-Assistant.556392.0.html