That is actually a wild headcanon.
Side note: That mysterious entity in her story trailer also made a re-appearance in her short story with Soldier 76. Hopefully it releases soon on the Overwatch website, so I can read it in more detail.
Reading these personal headcanons is making me glad that I made this post. I don’t think I could’ve thought up something as well connected as this for the Shimadas (or for anyone that I don’t usually play, for that matter).