I'm currently using this style in a RequireJS/Angular project. Everything works great, but it's pretty ugly. We should strive to not write ugly shit, but good clean expressive code. This is so non-standard it hurts. There are plenty of other ways the Angular team could have gone; CommonJS or AMD would have been better choices IMO.
ngmin doesn't work with r.js. My response was about using it with AMD modules. I know there were a few efforts to get ngmin/r.js working together, but last time I searched around I didn't see anything promising.