Ohio BMV does the same thing, at least I'm 99.9% positive they do, and they also deny doing it. One reason why I say this is my insurance company doesn't know my plate #, i.e. I never provided it to them. When I purchased my two most recent cars, my credit union didn't know my plate # either. Only the BMV starts with that detail along with the VIN, of course. If you use a auto parts selector, some sites allow you to input your license plate # (or the VIN or let you pick year, make, model) and it will ID your car correctly. I've also encountered it when getting auto insurance quotes online and after inputting some details, but nothing about our vehicles, it pops up a window asking "are these the vehicles you'd like insurance quotes for?" and it's correct information.The Illinois Secretary of State's office releases vehicle owner data (to outide non-governmental agencies), even though they firmly deny it.
As for my email address, now that online annual registration is so quick and painless, I've been using that and it asks for an email address somewhere in the process. I can't remember now if it's just part of the data they ask for or if it's for where to send the order confirmation and receipt. Either way, they can connect things to my email address now too.