Unfortunately, I don't think it's safe to say that, "Jaw surgery can fix the source of damage that occurs to the jaw joint due to unstable bite," but I could certainly be wrong (I didn't know where my maxilla was a year ago). From what I can gather, more often than not, it's a coin toss.
I used to have a terrible right jaw joint; I had osteoarthritis and was told there were lesions. I did the whole neuromuscular dentistry/functional appliance thing, and within 6 months my scans were substantially better. The lesions were 100% gone. I'm not recommending doing what I did (I now need surgery because it changed my bite), but I'm just saying that it's obviously possible to reverse damage. (The surgeon who took my scans said he had only seen an improvement that substantial one other time in his career---and he's not exactly a spring chicken.)
If you remove/eliminate/improve the source of the problem, I would absolutely say there is hope for your body to repair prior damage. Bodies are built to last, and given the proper environment they can do some pretty cool stuff.
Good luck with everything!
