Over on EW.com, David Ramsey, who plays John Diggle on Arrow, did a bit of a death pool with the site, running down who might or might not be in the grave visited by Oliver Queen and Barry Allen in the season premiere. We've been ruminating on that ourselves since the first instagram shot of the pair in suits in a field (which we assumed correctly was a cemetery).
He cautioned, though, that he genuinely doesn't know who died and is in that grave.
"It makes for a great work environment, doesn’t it? You’re on your best behavior! It’s like I used to be late to set, now I’m not. I asked. I wanted to know. Is Diggle dead? Is it me? They didn’t tell me," Ramsey told the site.
Ramsey gave his opinions on his own character, Diggle, Felicity, Laurel, Thea, Lance, and several women from Oliver's past. While he doesn't come up with anything huge, he does hint a few things, like the lack of flags and other military pomp (most likely eliminating Diggle, and perhaps Lance), and Oliver's level of upset. It can be assumed that if someone like Felicity or Thea died, Oliver would be way more distraught than he was in the scene.
"I don’t even know if [Oliver] would be able to talk if it was Felicity. He would just be so broken," Ramsey said of Ollie's paramour. Also, "If you take Thea, his whole family is dead except for him!"
One character they don't at all mention? Roy Harper. We know he's coming back to the show because of a blackmail plot, but having a fan-favorite return as a guest star would also make for a great moment to kill someone off. Not including him at all in this piece certainly throws up a red flag for Roy fans.
Of course, as Diggle noted, with "time travel and parallel Earths" now involved, "it's an infinite amount of possibilities that could be in that grave."