Board Thread:Theories and Speculation/@comment-30355627-20161218164138/@comment-734582-20161221215350

Elveonora wrote: 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. It was also never clarified whether an Ashura transmigrant getting Uchiha flesh can get a rinnegan. It's explained that the combination of flesh brings out Hagoromo's chakra which in turns brings out the Rinnegan, suggesting that you don't need a Sharingan to get it.

This, combined with Kabuto's incomplete hypothesis and statistical bias (We only see two Uchiha getting it) suggests that it's simply impossible to consider it verified.