Board Thread:Naruto Discussions/@comment-26320638-20150422140407/@comment-5936871-20150423021330

@Legion Obito knew that Naruto needed the chakra of all the tailed beasts for a reason. Which is why he specifically gave Naruto Shukaku and Gyuki's chakra so that Naruto would officially have the chakra of all the tailed beasts. It wasn't until he had all of their chakra that he met Hagoromo, and the power of all the tailed beasts AKA the Ten-Tails has been called "Hagoromo's power" several times because he was it's first jinchuriki and mastered it's power. So clearly the reason he met Hagoromo was because of the tailed beasts. Which is why it makes sense that Sasuke met Hagoromo because he awakened Hagoromo's chakra due to receiving Hashirama's cells and inturn his chakra as well.