Ha, maybe they just need to 'light up' instead. Be chill people.
I think using pot in the early post op period is a bad idea. Bad for the respiratory system mostly.
Also, if you can continue to be only an occasional user ie. once a week or less, then I don't see much harm once you are completely recovered. But as others mentioned I would be concerned if you became a more frequent user. I would worry that stressors of WLS and ongoing life changes that occur with same might be a trigger for cross addiction. The comfort of over eating is gone, and it would not be great if pot filled the void.