no, they are doing it to prevent lawsuits. In fact, on Ford's Sync 3 system, they have a huge disclaimer that pops up when you enable Android Auto or Apple Carplay, saying that anything that comes up on the car's screen is controlled by Android (or Apple) and therefore Ford is not liable -- go sue them instead.
http://drivinglaws.aaa.com/tag/telematics/
there are exemptions of some kind for navigation systems in many places.
I've heard "it's not allowed by law" often, but I have yet to track down the actual law. Hopefully automakers aren't doing this based on hearsay....