I have seen that hosts in my area have superhost for all their listings, even new ones. It says "Hosted by __________, superhost", even on the new listing. I have only one listing, so this is only from my reading my local area's listing to see what other hosts are doing. I a sure other more experienced hosts could give you more details about this question.
yes you are a Superhost. When the new property is listed it will say it is new, and it will refer the guests to the positive reviews on your other property and say you are a Superhost so the new property will benefit from your hard work. The bad thing about this is it can go the other way as well, if you host a home that turns out to be a problem house it could cause you to lose your status.