I think you’ve misunderstood. By dual screen they mean split screen. Eg. The main dash screen will support two apps side-by-side, eg Apple Maps on one half, Apple Music on the other (if you want to). This doesn’t extend to the AID. The inability to display the same thing on the AID as on the main screen is a VW limitation, not an Apple one. NB split screen in iOS13 will be limited to native Apple apps initially, ie it won’t work with Google Maps, Waze or Spotify (in split mode).