My wife has a surgery scheduled this Monday (4/11/2022) at a local hospital in the metro Atlanta area. We just discovered that the authorization request sent to our insurance company by the doctor is still pending approval. This, I believe is because the doctor waited until just a few days ago to send it them. I assume if we proceed with the surgery before it is approved, we could be liable for the entire balance (this is cancer surgery, so the tab is going to be $$$,$$$). Should we proceed with the surgery anyway under the assumption that it will be approved (I think it is mostly a formality) or cancel it. What, if any, is the charge for cancelling a surgery at the last minute. Can’t talk to the insurance company until Monday, they are closed on the weekend. Surgery is scheduled for 11am this Monday with check in at 9am.
If it was me and mine, I would make it their problem by showing up, checking in and then informing them that they cannot proceed without written notice to me that the operation will be paid for by my insurance company.
And I’d get it writing for sure, if not I’d raise a stink and insist on seeing the hospital admin director. You may want to contact your local TV station’s consumer advocate and advise them of the situation… things could get interesting… 
My wife is at MD Anderson Cancer Center Houston. They have a whole team of financial clearance specialists who do only insurance pre-authorizations. Your wife’s doctor dropped the ball. I hope it worked out OK.