When asked whether Slade Wilson or Walter Steele will reappear on the show, he replied, "The character of Slade Wilson is currently tied up in another DC project. Walter is more likely."
Prior to Deathstroke, characters like Deadshot and a potential Harley Quinn -- both of whom will show up in "Suicide Squad" -- were also removed from "Arrow's" roster, and many fans believe this is due to their appearances in the upcoming film. Though Guggenheim says Amanda Waller's death "wasn’t mandated by DC," some fans believe she was killed off in a recent episode of "Arrow" for this same reason. Since Deathstroke will not return to "Arrow" because of his ties to another project, some speculate this may mean the character is headed to film himself, though it isn't clear which or when.
"You said that only Deadshot was off-limits, and Amanda Waller & Deathstroke are safe," said another fan. "But you guys killed Waller off just like that, and she doesn't seem like she will ever return(Because bullet to head). Who's next to be killed off? Katana? Once Deathstroke arrives in the DC movie, will he be also killed off too?"
To which Guggenheim responded, "Um… I never said that."