Wild ideas from me. Evil Lana secretly replaces real Lana in some kind of super incident and claim amnesia. These episodes clearly show that Supergirl doesn't exist or does the rest of the Arrowverse crew in this world. Try to merge worlds and Spectre/Ollie doesn't show up! Evil Superman from John's world shows up and clobbers everyone, Ally, John, Clark, Jordan, Lois, etc. Just plot ideas.
Great show, so much better than the rest of the fading Arrowverse.