Why add all that fat to a post-workout shake? It's going to drastically slow down digestion, not allowing you to get the benefit of a surge of carbs & protein in the post-workout window.
And yeah, it's true that coconut is predominantly MCFA, which tends to just get burned up as energy. But it does still have a fair amount of LCFA's, so it's no magic bullet in that regard.
I also recall an argument that consuming a lot of MCFA could actually be detrimental to an extent, as your body is going to preferentially use that as energy, and may not end up tapping into your stored energy. I'll have to do some digging to elaborate on this one.
“The whole concept of a macronutrient, like that of a calorie, is determining our language game in such a way that the conversation is not making sense." - Dr. Kurt Harris