Board Thread:Theories and Speculation/@comment-45444155-20200806114740/@comment-6769189-20200807193144

Past Uchiha and Madara didnt need Senju DNA to use Izanagi.

Kishimoto made a retcon, Obito's words dont matter. Kishimoto changed the requirements for Izanagi later on, and in doing so made Obito's statement partially incorrect. Thats all there is to it.