People with severe obesity who undergo bariatric surgery have a higher risk for fracture both before and after the procedure.

“To minimize the effect of bariatric surgery on bone, guidelines should be followed and the importance of adherence to supplements and physical activity should be reinforced among patients and healthcare professionals."

https://www.healio.com/endocrinology/bone-mineral-metabolism/news/in-the-journals/{7e479b49-f551-4de5-a2c2-03b0718b1bdf}/fracture-risk-increases-with-bariatric-surgery

IMPORTANT: Take your supplements! Vitamins! Minerals! And don't forget to excercise!

Note that when an article refers to "bariatric surgery" or "weight loss surgery" in the general sense - not specifying any particular procedure, they are typically referring to the RNY gastric bypass, as that is, or has been, the most common procedure over the past 20-30 years (and particularly in Canada and other countries that may have been slower to adopt newer procedures). If you have a different procedure, the article may or may not apply to you.

The warning may still be valid - changes in diet after surgery may result in deficiencies even of the procedure that you have doesn't have any inherent relevant malabsorption - and the advice may still be sound - keep up with labs and maintain appropriate supplements, even if they may be different from what is anticipated in the article.