It won't do 12.7 stock, that's on a prepped dragstrip. C/D says they don't test on prepped strips, but that's only for certain cars (like Hellcats and supercars). However, many of the AWD cars were also tested on prepped dragstrips (like the "9-second" 911 Turbo S and the M5/M8 twins that did mid-10s).
It's all a marketing/salesperson tactic to prevent themselves from getting sued because many powerful cars suffer from traction issues.