What if it was actually Bart in the wand? I know that when he died he was depowered, but the Black Flash was there for him...what if the wand somehow gathered his spirit from the Black Flash in the moment of his death? Age-wise he fits into the Legion, he's from their era-ish, he has connections to A Legion through XS, and we have creator comments suggesting that his story isn't over yet. What if it his spirit that we see in the wand?
I like this idea. Barry should stay dead--someone has too
and his death was pure heroic triumph. Let it be Bart. Let it be Bart!