In the episode, McKay mentions meeting another version of John Sheppard, but hasn't met the one in this world. That means he's not the Rod who came into Atlantis through the bridge created by McKay and Mrs Miller, who talked about his John Sheppard as being a pain in the ass and leader of Mensa on Atlantis, or some such.
So this means this is an alternate reality episode with no connection to our world except the danger they unleash at the end. With so very few episodes left to the series, I was hoping for something memorable. Instead, we didn't even see half the regular members, and not a stargate in sight. Sorry, I don't like the wraith particularly, am not a John Sheppard fan, and like the team as they are, not some alternate reality version. This felt like a very poor fanfiction, not the brilliant writing we've come to know and love.