If they mean the connector that goes from C to the D/E complex, there used to be a UA club along that corridor. I don't recall when it was closed and if anything has taken it's spot. Could this be the location? Or do they mean the D/E connector to be the area of shops that connect D and E? 20,000 SF is a lot so I'm trying to picture where this would be in that area.
I took it to mean the D/E connector that opened for the consolidated security checkpoint. The UA club is still alone between terminal C and D.
I'm guessing a lounge that big will be "upstairs" somewhere.