John Diggle, who plays Arrow, may still have a future as an Emerald Knight. While at DragonCon (via The Direct), David Ramsey discussed Diggle's potential Green Lantern future.
Diggle took on the role of Spartan in the Arrowverse, starting in Oliver Queen's (Stephen Amell) bodyguard, but later joined Oliver in his quest to save Starling City (which later became Star City). In Season 6, he even took on the role of Green Arrow after Oliver temporarily retired.
Diggle has appeared in other Arrowverse series since the season 8 finale, with the box seemingly coming to an end, although Ramsay said the Green Lantern story might continue outside of the Arrowverse on Superman & Lois.
"And the reason why he did it is because the Arrowverse was about to end, right? And we knew, not at the time, but you didn't know yet, that Todd [Helbing] was going to reveal in Superman & Lois that the Superman & Lois-verse, if you will, exists on another planet on a different Earth."
"And the reason why he did it was because the Arrowverse was coming to an end, right?" We knew, not at the time, but you didn't know until the next day that Todd [Helbing] was going to reveal in Superman & Lois that the Superman & Lois-verse, if you will, exists on a different planet on a different Earth."
Superman (Tyler Hoechlin) explained that the series was not set outside the Arrowverse, and that Michael Ramsey has also appeared in Superman & Lois, playing a different version of John Diggle. "It was smart because it allows us to develop outside the Arrowverse, which we weren't permitted to do," Ramsey said.
In 2023, The Flash and Superman & Lois will return on The CW with new episodes. In the meantime, you may watch a new promo for The CW featuring Superman & Lois: