User blog comment:Sorokaj/Theory/@comment-1330227-20170528181811/@comment-24152851-20170531035638

Ghosts wouldn't be main cast members. Unless they're literally haunting around in every episode. The only way a postmortem Arrow character could be a main cast member would be in the flashback timeline, though there might not be any more of those since Oliver's 5 year gap has been filled in.