Aye, but as boxers we need as much LEAN MASS as we can find. A protein shake (unless pure protein) has enough in it to inject the protein to where it wants to go (aslong as your eating right)
Bodybuilders use a lot of techniques that boxers definately shouldnt. This being that bodybuilders aim is to gain weight, and as quick as possible. A lot of the side effects of this being detrimental to boxing.

Your probably right about the muscle milk, ive never seen the stuff. But an average protein shake is not good to take before bed, as it will stop supplying the body with protein within an hour or so.
Flax seed or like you said cottage cheese are a lot better.