Oh, contrare....
On GM vehicles, which has been this way since at least 2000, when you put a vehicle in low, then tap it into 2nd. gear, it is know as a "low torque" takeoff, used for snow/icy conditions, and the vehicle will start in 2nd. gear. Same thing goes for the column shift. I start my Silverado out in 2 all of the time when it's slick out. Starts in second, then will stay in 2nd gear yes, but I can upshift to D when moving.
From everything I've been told, the original poster is 100% correct in his statement. It is also correct that the transmissions will not shift to a gear higher than what you have selected, but it will start in that gear. ( 2nd. )