I've worked in the bicycle industry for 30yrs and was National Team and racing full time a long, long time ago. In July I'm glue to the tube.
The moto drivers must go through many years and many steps before they are allowed to be part of something like the TdF. In the Tour of California several pro bicycle race moto drivers come over from Europe. I remember watching a moto with the photographer standing as they descended Decker (one of the most technical descents in the Santa Monica Mountains) and they were flying. I regularly chase and sometimes pass sport bikes on this downhill, it's tight. When a team on a moto have worked together for a while they are amazing to watch.