Board Thread:Naruto Discussions/@comment-9567825-20140910102105/@comment-10330822-20140910120058

MERCURIOUS wrote: Well, since to stop the IT, you need Rinnegan and the TB Chakra. That's why even if he killed Naruto, he still has the TB Chakra in the Chibaku Tensei.

That would be if he could channel the chakra via Chibaku Tensei, but we have no reason to believe that. He probably would release them after killing Naruto, and then release the beasts to release the IT. Although, I think he's planning on trapping the beasts in Chibaku Tensei and sending them into space, because they are indestructible otherwise.