Well he is Madara after all. They've never really shown or explained in anyway what abilities and jutsu's he was capable. And from what we know he lived a very long time before he passed away. That's a lot of knowledge and secrets he had time to learn but maybe not utilize due to his ailing health/age. Now that he's back, alive, and in essentially the prime of his youth I am sure he's quite capable of many things. Things even he couldn't do before when he lived.
So, yeah. Perhaps he only told Obito of one way of utilizing the statue, and well.. quite obviously the damn thing can do a lot more than we originally thought way back at the time Shukaku was being separated from Gaara.