Ask and ye shall receive...
I recently got the update to 6.1 firmware. Last night when leaving work I was a bit too eager shifting from P to R (car hadn't quite started up yet), so I pressed the accelerator while still in P. Sure enough, triple-beep, and a message along the lines of "Please shift to D or R to drive" appears on the dash! I quickly tried shifting to neutral (while still parked) and got the same message when stepping on the accelerator.
Not nearly as snarky as my earlier suggestions... and likely in the works before this thread even appeared... but much appreciated regardless.