Well, Naruto already has every single bijuu's chakra. He received some when he saved the bijuu's, he already has kurama's, and he's had the eight tails chakra inside him for quite some time now.
Remember when he trained with bee.... Well during the training, bee went inside Naruto's inner conscious to help handle kurama... Well there is a panel/scene where bee tugs-or-war with kurama's chakra, and he inevitably loses and Kurama absorbed an entire tentacle
Now, how much Chakra of the hachibi was needed for the juubi to come alive?.... 1 tentacle... Not to mention only a bit of kurama's chakra.
Now I'm only speculating, but I believe Naruto already has the NEW juubi inside him, and the body/host for the 10 tails chakra is none other than Kurama. This allows Naruto to already be the jinchuriki without a sealing process, plus it'll still be Kurama's conscious. The only real thing missing is the other half of Kurama's chakra, which might begin the entire process.