Good points. I also wonder about cars like mine and a few other members, which were built as GM Media cars (or even that one listed for sale that was a Central Office car). Given that GM initially announced 275 CT6-Vs, and then (due to demand?) followed up with another 600, and then promised 600 more for 2020, we all go with the 1,475 number. But my media car (and several others that made the Auto Show circuits in the winter of 2018) were built before the 275 that the initial owners got. Are they extras (along with the at least 3 Premium Luxury cars)?
I also test drove one of the three cars for sale at a Detroit-area used car lot that came from GM; all were durability test cars with ~20,000 miles on them and no factory warranty included. I wonder which number they were included with, if any? (One of those, btw, was a gorgeous Satin Steel Metallic V with Dark Auburn... if it had had the Driver Assist package, I'd probably be driving that one - warranty or no warranty.)
I'm sure someone somewhere in GM can run the numbers from the Hamtramck plant and discern how many Blackwing-equipped cars made it out the door, but we may never see that information. :-(