Tril apparently the PCOS tends to operate in the same was as type 2 diabetes in that you get into the fat-can't exercise-slow metabolism-get fatter cycle. Often the drastic reduction in food leads to weight loss - you can still have PC ovaries, just not the "syndrome" part of it IYKWIM? But you are right in that it is something to bring up with a doctor.
One of the biggest probs with not losing weight after the surgery is people who want to be fat and sabotage the procedure by drinking milkshakes or eating melted mars bars and icecream (ie: easily digested high-kj food). Mum met a man who gained 5kg after the surgery by throwing up after each meal and gorging himself again.
So another thing to consider is being the the right headspace before having the procedure....