"Nightwing." Dick keeps his position on the launch pad, solid and stoic, but now he knows who is under the mask, so he releases the breath he'd unconsciously been holding.
Another version. And as Robin this time. I think it's safe to say they could definitely rule out Nightwing's- the other Nightwing's idea that the portals were following orders from someone. This had to be random. Three Dicks? Jesus. ...But what were the chances? And within so many days of one another, too. Maybe it was too coincidental ...or maybe they just didn't know enough.
"And you're Robin." Still, they couldn't rule out the possibility that he was a plant, perhaps even bugged. So no names. Not until they know for sure.