Board Thread:Spoilers!/@comment-10663213-20180310035130/@comment-27060727-20180316201622

Avengingoncer wrote: Yes, but original Robin has no ghost or soul. They made that clear in S5 if I’m remember correctly. He can’t be resurrected I'm not talking resurrection. But they can always come up with another method to reach Original Robin regardless of wherever he is or what he is.

They did say that his soul was obliterated but then in early season 6, the writers went back and told us that maybe Hades was lying and Robin went to a better place after all. So now it's up in the air if they want to confirm it canonically or not.