I'm pretty sure every 2012 has it; mine does. It's a surprisingly large button actually.
Disabling TCS and ESC doesn't completely disable it though, it just delays the point at which the system intervenes. I went to a large open paved lot where they sometimes hold autocross competitions (I used to go there to have fun with my Sentra SE-R Spec-V), and even with the TCS and ESC off, I could never get the Volt into a 4-wheel skid. It was super easy to do with the Sentra which had no electronic aids of any types, not even ABS brakes.
I would also expect some tire spin at launch with over 270 lb-ft of torque, but it's hard to get any at all.
I'm not saying this is a bad thing, because I can't think of a reason to want to skid a Volt intentionally, but GM shouldn't say that it disables the system because that's not what it does.