There are a lot of variables, so no stock answer. For example, some insurance providers require a six-month diet/wait period; some require different numbers of visits to a nutritionist. The pre-op testing can also vary--I've been told my lung clearance doctor *may* require a sleep study.
On the other hand . . . however long it takes, what would be happening if you weren't going through the process?
I've seen some people get scheduled within a month or two and others who report waits of nearly a year. I had my first appointment with the surgeon on May 10th and have a tentative surgery date of August 28th, but a LOT of clearances to get before then.