I'm not sure if "shortcuts" should be taken in orthognathic surgery.
I'd agree with this, I think there's just a market for people who might do that, whether it's a riskier surgery or not, because people don't want to deal with upwards of a year in braces, exacerbating their bad bite before surgery. I think in the long run though, it's probably worth it to go with the tried and true methods. My orthodontist and surgeon insisted on having the teeth in nearly their final positions before the surgery.
Also, if you're having your jaws wired shut, I'm guessing it'd be harder to do that without braces to hook the wires and hooks onto. Probably not a big deal, but still.