no good call on recycling the old thread, better than making a new one...
Chocolate milk is ok post-workout, mainly because it contains milk proteins (whey and
casein), and has a good amount of carbs as well, also has sodium and potassium which are good post workout...
However, the amount of protein in a typical 500mL serving for most people wouldnt be enough for a post workout supplement, I personally take about 35 g protein post workout (guys with more muscle mass take more) and the typical amount of protein is only around 16g per 500ml.
Now you may think "well then Ill just drink a litre post workout" but that wouldnt be the smartest thing to do, first off that would be brutal on your stomach, you would most likely puke, and also you would be taking in upwards of 100g of carbs, most of which are sugars
So to sum it up, Chocolate milk is an OK post w/o supp, but definitely not a first choice, I would much rather drink a shake containing a quality whey isolate, maltodextrin/vitargo and BCAAs, it would probably be more cost effective to just buy those three ingredients as well...
Just my 2 cents tho