I also have BCBS of Ill. I was approved. My BMI was just over 35 and I have several co-morbidities, including sleep apnea and have had a heart attack.
Requirements were one appointment with Dietitian, session with Surgeon, and psych evaluation. I believe this varies company by company (or by your group) so you'll want to talk to the insurance company directly to find out specifically what applies to your plan.
Once everything was submitted, the approval came in just a few days.
Good luck!
My husband works for AT&T we have BCBSIL as well and I am about to start the process to try and have my weight loss surgery covered. I hope your appeal goes well. I am praying praying they cover mine. It's my last option I have tried everything else under the sun.