It's not really different than losing weight by any other method in that respect.
There is always the risk of regaining weight unless you continue to do whatever caused you to lose weight (e.g. restricting calories) to some extent.
I guess a "cure" would be good but since we don't have one having to periodically go back on glp drugs if you gain weight is no different from periodically having to go on a diet if you gain weight.
On the other hand most people tend to naturally gain weight pretty slowly (e.g. a pound a year) so having to go on glp drugs for a period every few years wouldn't even be that bad, especially if they're available in pill form.
It is mixed. It can be a cure for some people. Last time I looked my impression it seemed like about half the people has only moderate rebound or less.
You have a lot of results that look like this, with an average bounce rebound of 2/3s of the loss.
However, detailed analysis usually shows a bimodal distribution, with people who maintain or even lose more, and those that go back or even gain relative to baseline.
Treating the symptoms can be helpful in the long term if symptoms are a contributing cause to the disease. I used to ride my bike 150+ miles a week, but after not being able to do so for a bit due to other reasons I gained some weight. At the level of riding I was doing, an extra 20-30 lb of weight makes riding far less pleasurable, particularly when it comes to going uphill or on dirt paths.
Just finding 10-12 hours in which to exercise every week is challenging on its own. It's much more difficult when the exercise itself becomes harder and less rewarding.
Seems like GLP-1's are not a cure but treat the symptoms. You need to keep treating the symptoms forever unless you solve the issue.