You can bet gifts will arrive. I had an early reservation for a Model S (<2100). During the wait, a number of unexpected gifts arrived such as a hat (when you look at my avatar you will notice it has the Model 3 logo), insulated coffee mug, remote-controlled Tesla Coupe, and matchbox Tesla coupe (it sits on the brim of the hat in my avatar). The blue box on the base of my avatar contains the remote-controlled Tesla coupe.
Nobody really knows the formula for deliveries...maybe not even Tesla yet!
All that has been published that I know of was that after emplyees they would work from West to East based on reservation. Now, does a Californian that made their reservation in mid May get their car before a New Yorker that reserved the night of the reveal?