I was confused by the erased line. When she said the was no trace of the Black Canary, I wasn’t sure if she meant no trace of her as BC or any BC in history. I’m assuming since Mia had no clue who they were, any BC.
Side note: Remember in the Earth X crossover, Nazi Wells told Felicity that history remembers BC (among other heroes) but there is no mention of Felicity Smoak? LOL
KC keeps talking about E2 backstory so I’m not thinking there is a big twist with BS.