Board Thread:Theories and Speculation/@comment-34661853-20181111160651/@comment-4080775-20181112222320

Hago gave Sasuke half of his chakra directly. That is the reason why he awakened the Rinnegan. It had nothing to do with Hashi's cells being transplanted into his body.

If that was the case, then Naruto would have awakened the Rinnegan after Tsunade made him an arm cultured from Hashi's cells after the 4th war.