What I'm predicting is a ban on manual control in heavy traffic. Besides any throughput improvement, all-autodrive traffic will probably be safer, which is our priority (to an IMHO unhealthy extreme).
How will an eventual ban (after every vehicle has auto-drive presumably) on manual control have any impact on the initial take-up of auto-drive systems? What you're talking about (if it ever happens) will only happen many years after auto-drive becomes popular.