You can't buy a new bike without getting a title. You don't have to register it but the dealer is going to do the paperwork to transfer the title to you.
I do not believe this to be true at all.
You cannot buy a new bike without paying taxes on it, a dealer can do this for you. In some states a dealer can issue the title and tag for you when you purchase the vehicle new.
Registering a vehicle with the dmv and getting a title are the same thing. A new bike DOES NOT come with a state issued title that the dealer has to transfer to you. The MSO comes with a new bike and is issued by the manufacturer/dealer, the title is issued by the state. Generally, when you purchase new, you take the MSO and a hand full of money to the DMV to get a title issued by the state, mostly to track yearly taxes on said vehicle.