I wondering the same thing. But, I am on the other side. I think it depends on when the vehicle is put in actual service. If it hasn't been sold and titled or the dealer hasn't put in service as a Demo or Loaner then I would think a new car warranty would apply.
Definitely a question for clarification before purchase/delivery. If I had the extra cash in my wallet it would be a question I would ask.
Maybe GM designates a "New" vehicle, as one that has never been titled to an new owner other than the dealership? Don't know, maybe it boils down to interpretation...maybe is should be called "Unused". I have seen that term before.
I understand the argument that if a truck was never titled it is technically "new", but I cringe when I see demo units being sold new with 5000 miles or more, just not correct. The only way they get away with that is for financing and sometimes larger discounts.
So, lets say you buy this "new" SSR, then drive it home, only to find out that after sitting for 13 years the roof struts are leaking. No new OEM GM parts available, going to have to get some used rebuilt ones.
Have a problem with the leather cracking on your seats or door panel due to improper storage? No parts for that either.
Maybe a small fender bender on the way home. Most insurance companies are sending trucks to scrap yards due to no parts.
IMHO it is just not right to advertise it as "new" for the above reasons. They cannot support it and GM has few parts. Nearly all parts are now used or rebuilt if you can find them. After sitting for 13 years, I would be very suspect of all the seals no matter what they say they or previous owner did with it. I guess if you want to buy it at the premium and leave it parked and put it in a bubble for a future auction sale hoping to recoup some money it might work if you are young and can give it a few years.
I would rather buy a 5000 mile driven truck at 30k than paying premium for this one at $47k.