That does look like angel wing to me. We had an african goose with the same problem on one wing at a young age, but didn't recognize what it was until he was 3-4 months old. We took him to an avian vet, who tried wrapping - left it wrapped for 2 weeks. The vet said sometimes it works and sometimes it doesn't, but it's worth a try. In our case, wrapping didn't do the trick. We considered surgery, but the vet said just to keep the feathers on the wing tips (3 or 4 longest ones) trimmed back so the wing itself isn't injured further by the weight of the feathers and so that other geese (or ducks, in your case) couldn't pull on those feathers and do more damage to the wing.
I hope wrapping works for your muscovies, but just know that it's not catastrophic if it doesn't work. It doesn't really affect the duck's behavior or function.
BTW, the vet said this is usually the result of feeding rations too high in protein at a young age. Live and learn.
Good luck...and, congrats on your new additions!!
