Every hospital is a little different but I saw nurse, dietician, anaethetist and surgeon had weight and body fat measurements done as well as height, had pre op and post op diet explained, had bloods taken, had to give a urine sample and had a long chat with nurse and anaethetist about the op and after care on the ward.
I had my op delayed a bit after my consult with the anaethetist. He was worried about my breathing, so wanted to get me on my cpap machine first and asked me to lose a bit more weight. I was too high a risk at that stage.
Although I was upset at the time it was for the best,and I now have my date for end of April, have my cpap machine and am losing weight steadily.
As I said though every hospital seems to do things a little differently, and I'm sure a few others will jump in with info.
I don't think your op will be delayed other than if some kind of medical reason comes up, and I would think you would already know about it by now if they are talking about an op next month.