I didn't really have any health issues, but I'm also a "senior" - there are lots of us on here who've had surgery in our 50s, 60s, and even a few in their 70s.
not being able to exercise much shouldn't be an issue. Weight loss is 90% diet and 10% exercise (exercise has a greater effect during maintenance, though (once you reach your goal weight) - but then, you can only do what you can do. But for losing weight, no - it doesn't play a major role). I've "known" several people on bariatric forums who rarely if ever exercised, and they still lost a ton of weight.