I'm surprised that they didn't just make this a Smallville spin-off and get Hartley back. Having said that, I can see the attraction for a totally new slate.
Wonder if this means that the Supermax GA movie is dead?
Making it a Smallville spin-off would likely carry with it a lot of weight they'd have to deal with. The first being GA's relationship with Chloe, Queen's close friendship with Clark/Superman and, of course, dealing with Superman if even only in the background.
Indeed. Weren't Oliver and Chloe actually married by the end of the series? And you'd be constantly be running into the problem of "well, why doesn't he just get on the phone and call Clark . . . or Aquaman or Black Canary or Cyborg or Zatanna or Martian Manhunter . . . ?"
Better to start fresh, unencumbered by ten years of SMALLVILLE continuity.