It's not the post date - it's the date they verified the images for twitter on. That's what that twitter post was saying. People focusing on the post date are falling for a limited hangout.
I want to know more about this too. Some organizer get picked up clandestinely? Just some opportunistic criminals decide to snatch a woman of the street? False flag?
That's the assertion, yes. I tried to check the links today and got 404 errors on the archive and 401 errors on the current twitter card. Last night I could get to them just fine.