Per your first post, this was your friend so I would think if they were truly a friend, you would have gotten the correct story.
Yes, it could have been a promo bike taken around to shows. The MoCo would have taken that out of circulation once it had run it's course and offered it to dealers for them to purchase and sell.
Yes, you can purchase a bike and "pick it up" at the factory (or you once could). However you arrange the purchase through your local dealer and then arrange the date/time to retrieve your bike at the factory but you can't purchase directly from the factory.
As others have already posted, the low 73 miles doesn't make this 2010 any more special than any other 2010 CVO with only 73 miles on it, that just makes it an interesting find. Being it was owned by a friend may add some personality to it, too.
As for the VIN helping, it would only help if you wanted to contact Harley directly for some history...and that is if they would provide that information to you. You can do a VIN search and try that way via the interweb which may show you some history of where it was purchased/who owned it/accident history, etc.
Good luck...