They probably deloft it somewhere around 5-10 degrees depending on the shot, but the launch angle is only about 20 degrees. Remember a lot of spin is generated so the ball doesn't just jump off at the exact angle of the loft; it gets squeezed down a bit lower. I also feel they often deloft their short irons a lot, relatively speaking, compared to longer clubs. Something like a driver at 8˚ probably won't do this much, and they're designed to launch higher anyway.
Basically, the number you're looking for isn't called launch angle, but the answer to your launch angle question is about 18 degrees.