About 10 years ago I went through rapid weight loss using another method. Just as I was nearing my goal - lost a 100lbs - I had three very painful gall bladder attacks. I had it removed via laparoscopic surgery. It was day surgery, and I recovered quickly with no side effects. There are some people who can not tolerate certain foods after the surgery, e.g., fatty foods. I had a period of time where there was true, but it gradually faded.
Now that I had the band inserted, I have a bit more scar tissue all in the same area, but no big deal.
So, I had gall bladder surgery first, and then the band. Not the order you may be heading for, but if your surgeon performs both, it sounds like you'll be in a good place.