I checked when he was sitting down on the bed. The Curse seal is not there, meaning that it's hidden in the skin maybe Madara took the Cursed Seal off. Remember that Madara is at level Kage and so making seals and taking them off wouldn't be a hard task. If Kabuto can't control The White Snake in him the Curse Seal will return on Sasuke's skin or say he fights Sasuke and gets his ass handed to him, then The White Snake would take over Kabuto's body. Which would bring back the Curse Seal on Sasuke's neck. Without the Curse Seal Sasuke can use his eyes more and will be able to extend his chakra, meaning he will be able to fight longer and we will see him turn into a Hawk...:sasuke: