That makes sense now.I just received my invoice earlier this week along with that form. If you could see the whole form, it is just a dealer authorisation to register form, not a registration form. So literally the simple form to fill out which authorises Tesla to register your car.
Tesla supplies slimline plates by default (black / white letters). I’d just tick slimline just in case, fill out your name and license number, sign and email back. Everything else done for you.