In general you want to follow order of operations. Less risky procedures first, then see if something more extreme is needed. But beyond that, Kavan is right, in that the bite wouldn't fit after expansion. Since the lower jaw can't be expanded in any real sense (just flaring teeth), you could have a serious bite problem in that situation.
You can probably find a surgeon willing to do anything, though. It wouldn't surprise me if someone would do this. But ask a reputable surgeon and get the answer, and if it's different than what we're saying, let us know.