I don't think Bariatric surgeons tells what to except in terms of detailed weight loss. They went you to come in every couple of months and will ask a couple of question and will how he sees your progress.
I hate going to the doctor and Covid19 didn't help. So, I asked a surgeon friend of mine(not bariatric surgeon) what to except in terms of weight loss in first year and he said if you stick to your diet and calorie intake on average except to lose
1 month: 10% of your weight
3 months: 20% of your weight
6 months: 30% of your weight
12 months: 40% of your weight
and my weight loss fits exactly with this except for the 40% weight loss mark which I reached by 10 Months due to higher exercise intensity and really watching what I ate 6 months after surgery. My BMI was around 40 and I had no Pre-OP diet requirement, so I didn't lose any weight before surgery.