I agree, and I really have tried to find success stories about water fasting resolving eating disorders and I can't find any. All I can find is some testimonials relating to juice fasting being of benefit, which of course is actually not a fast but a way of eating healthily.
During my search though I did find an interesting 6 minute YouTube Video which I thought was worth posting here. I can identify with some of the things this lady is saying from my fat years, for example "I don't have to deal with my own emotions when I am eating this bag of chips". There was a time in my life after I had given up smoking and when I still had a few issues and over ate. I suppose then it could be argued that I did have an eating disorder in the past, but then that could be said for anyone who overeats - and a lot do! However I know for sure I was not suppressing my emotions at the start of my fast, and if I think back I know I could never have fasted when I had the hangups I did many years ago. Or if I did, it would have all gone back on for sure, and I would have felt worse. That was exactly what happened when I tried to diet in the past, I was starved of my comfort foods, poor me! Anyway from a personal point of view I guess I completely agree with the underlying message in this video, which is sort out your emotions before you fast. Looking back, I can see that this is what I did, and that's why fasting worked for me.