Surgeries come and go. In the early days, surgeons stapled stomachs and wired jaws shut in a dismal (in hindsight) effort to help people lose weight.
Weight loss surgery (WLS) has come a long, long way. WLS is an evolving field. It is no longer restricted to those who are massively overweight because the surgeries also help improve the metabolic health in other ways: better diabetes control, improved fertility and pregnancy outcomes, better blood pressure control, and lessened inflammatory concerns in joints and other parts of the body.
Surgeons seem to love a challenge. They pick up on scientific advancements with enthusiasm.
Advancements in equipment and technique (robotic surgery, laparoscopic surgery rather than cut-you-wide-open surgery, suture materials that don't fail quickly), in evidence (published and from peers' experiences, and experiential evidence within a surgical practice).
Some procedures barely make it off the drawing board, others advance to accepted practice. Some get stuck in research laboratories with obese rats as test subjects. Others fade into history.
What is important for you to ask your surgeon is how long he/she has been doing the particular surgery, how many cases they have operated on, the results, and risks within his/her practice. You don't want to be on the surgeon's steep learning curve. Reports from conferences suggest that a surgeon needs to have performed at least 100 cases of a specific surgery in question before they are even close to competent.
You want to know the surgeon's track record as well as the international track record for the specific weight loss surgery offered.
Similarly with dietitians. Just because a dietitian has 20 years experience doesn't mean he/she has enough specific experience in your health concern. The dietitian may have only ever seen one other person who has had weight loss surgery. Their specialty may be allergies rather than weight management and surgical weight management.
Weight loss surgery is changing its name to metabolic surgery.