I'm pretty sure every player at the elite level uses wrist when looping.Does Ma Long uses his wrist, when he strokes his forehand topspin ?
Actually i don't think many chinese players use their wrist in the forehand. It only comes to mind Chen Qi due to his european style grip, maybe Yan An. Ma Long has closed grip making it very difficult to use the wrist in the forehand but very easy to do that in the backhand.