Well we are now under a week away from Katie’s next Arrow episode 5×10 – Who Are You? and as the last trailer gave it away (great job to the person who put’s there together there) Katie will be playing Earth 2’s Black Siren not are Black Canary who is still dead, There is no talk about Katie being in episode’s after this one so I guess we will have to see were she end’s up at the end but my guess is A.R.G.U.S. Till then you can watch the extender trailer below and read some things Greg Berlanti and Marc Guggenheim have said.
TV Line: Following his appearance at the Television Critics Association winter press tour (for The CW’s “Behind The Heroes” VFX discussion/demonstration), Arrow co-showrunner Marc Guggenheim was asked about the aforementioned overshare.
“Without commenting on the promo, which I have nothing to do with…,” he diplomatically responded, “[and] without commenting on the spoiler, I would say that the episode ends with laying a very specific seed, with a very specific game plan on our part that we hope to see come to fruition.”
CBR: On Katie Cassidy’s unique return to the “Arrowverse” after Laurel Lance was killed off:
Greg Berlanti: We made a deal at the end of that season to bring her back for a bunch of episodes. Katie is a part of the fabric of the show. Because the show, like a comic book, can move in different ways, and characters go and come, everybody that’s ever been a part of the key and core ensemble has always had a place at the table for our show.
There’s the capacity for her to be [in all four shows]. At this moment, she’s in three of them.