I didn't know that. My current car is a 2012 Prius Plugin Advanced and when this house was built I had the garage prewired with a 220 line for a Level 2 charger. At that time a lvl 2 charger required a 30a circuit so, rather than future-proofing the run from the main panel to the sub panel and plug for the charger, he put it on a 30a circuit wired for 30a not 50a. It is 50a to the subpanel. Sure, would I have liked a 48a circuit for my model3? Of course. Do I need it? No. There is likely an 18" run from the subpanel to the plug which is an orange insulated 3 prong wire. If I am not mistaken that orange color is coding for 30a max. Now that the garage is insulated and drywalled I don't know that it is important enough to replace that 18" length of 30a wire with an 18" length of a 50a or 60a wire. My belief is that the run from the main to the sub could take 60a so running the sub at 60a is the cost of a breaker.
While I didn't know there was a distinction between when one purchases the Tesla charger, that wasn't really my point, the expensive part, seems to me, is running a line to the garage and to where the charger will go. Having the charger wired is small compared to the creation of a subpanel and 60a circuit for the charger when you get it.
Oh, you've ordered the entire thing through Tesla? I thought one would order the charger and have some local guy install, pretty much how I got the Leviton installed. Of course the Pruis charges on the passenger side whereas the M3 on the driver side.