If your bmi is over 35 or 40, it doesn't matter, but if it is below then yes, i think there needs to be something like sleep apnea to cover. They should cover it. You can even call BCBS to give you the benefits, and they are very helpful. I have bcbs of Illinois, and they told me that it was covered and I read the guidelines. I hope it goes fast for you too!
One more thing, I do know if you have sleep apnea, they want to see that it is managed, at least through my doctor. You have to get a pulmonary clearance before therapy. If you are currently using a cpap, and have already had a sleep study, then you don't have to do that.