User blog comment:Sci100/Sci100's Speculation and Theories on the Arrowverse Flashpoint/@comment-4969948-20160527024854/@comment-4050367-20160529013158

I think that the Flashpoint Paradox will lead into the Arrowverse characters entering Supergirl's world during Supergirl's crossover episode. When the timeline is corrected, the versions of the Arrowverse characters that went to Supergirl's world will have never existed, affecting Supergirl's world too to the point that it causes both universes to merge. Plus, we don't know the full extent of the "Magnetar" and its brief usage on the multiverse so that could also play a role in Supergirl's universe.