Watch for Insurance Changes!!!

Hi everyone! My surgery is scheduled 3-8 I am very excited. I was told by my nutritiionist to watch out because 2 people with my insurance were cancelled the day before d/t a new rule BCBS has that says you have to have documentation by physician that you have been on a supervised diet that failed for 12 months. Well I called my insurance company and they told me there was no preauthorization needed for surgery so I was relieved and then last week I went to pick up my final paperwork from my surgeon for disability and the secretary hands me a form that has to be filled out by my primary care doc stating I have been treated for 12 months!!! She says if it is not filled out my surgery will be cancelled because insurance will not pay without it!!! I start to friek out. Luckily my PCP filled out the form for me but she didn't have seen as though I have only been seeing her for 10 months!! Watch your back with this one. Even the insurance company didn't know when I called them