You're dreaming if you think you don't need to wait for the Mach-E specialist to get your car serviced. Hopefully, Ford mandates that dealerships train more than just 1 tech on the Mach-E. That 20k production tells me not that many techs are going to study up on it.
Your examples ain't quite working. Tesla actually did a very good job of servicing things at Model S production ramp up. In that 20K production world of yours.
The problem was that Elon was bleeding bucks, and the first thing he threw overboard was the sales and service organization.