Board Thread:Theories and Speculation/@comment-30355627-20161218164138/@comment-1512913-20161221210458

But it was only a hypothesis which is actually untrue, since combining chakras of Asura and Indra present in their respective reincarnates recreates Hagoromo's chakra and thus the Rinnegan.

Adding Senju power to an Uchiha doesn't change his/her Sharingan into Rinnegan, nor will a Senju receiving a Sharingan transplant change it into a Rinnegan.