The way the metric is designed is dumb so they do their testing elsewhere. It is a California rule. Basically if you wanted to game the metric you could just drive an autonomous car around a circular track and have no disengagements. But anyone trying for true level 5 is going to have to have lots of disengagements along the way towards training the system. So if Tesla put their actual numbers it would look really bad because city driving is very different than highway driving. And of course all the Tesla haters would go around talking about how their FSD system sucks which would hurt their stock price which would hurt their ability to raise money which would reduce their R&D spending.