Authorized but not really?

My Patient Care Advocate submitted my packet for prior authorization to BCBS of AZ and we received a letter stating that based on the information received ,my insurance does cover this procedure and I appear to meet the guidlines of it's medical necessity, but it also states that this is not a guarantee of coverage and it's not a pre-certification.  The surgeon's office seems to think this is good enough to schedule surgery, but I'm concerned about the carefully including wording stating this isn't a certification.

Has anyone else had experience with this?  Because my LabBand surgery is being scheudled as an "out-patient" procedure not involving an overnight stay, I can't get pre-certification.  How likely is it that after all this, my insurance won't cover the claim afterwards?

I had a very simalar letter from BCBS of TX.  My Dr. said it is very common and they are 99% sure there will be no problem.  That is good enough for me! LOL