I have a theory that people will keep seeing better success with species of fish that used to be thought of as Impossible, like the Moorish Idol, Clown Tangs, Regal Angels, and others. I think this is due to 2 reasons. First, collection practices have improved quite a bit leading to many people having a much better chance at a quality fish from the start. And second, our aquariums have gotten bigger, with much better nutrient export allowing people to feed their fish much more often. Looking at the Idol, there doesn't seem like much room for storing fat reserves, and from what I can tell, they seem to have a fairly inefficient digestive tract. I think they need to be fed often throughout the day to do well. In the past feeding a lot meant you were going to struggle with a lot of algae. Now however we have much better skimmers, carbon dosing, and other methods that allow us to feed a lot and maintain water quality.
Sorry for the tangent, your Idol looks great, I hope this is just the first year of many!