Here's some scoop on Arrow from Entertainment Weekly's Natalie Abrams' The Spoiler Room column, which was posted on 3/3/17.
If Chase is Prometheus, then who is under that Vigilante mask on Arrow? — Maggie
Alas, we won’t find out soon. “We know the answer to that,” executive producer Marc Guggenheim says. “You probably will not get the answer to that in season 5.”
Link to the full article:Spoiler Room: Scoop on 'Once Upon a Time,' 'Arrow,' 'Supergirl' and more