What I mean is, nothing about the stories of the survivors would indicate that these pointy-eared, green-blooded people were Romulans.
Perhaps, just perhaps, the survivors would have been eavesdropping on the conversation aboard the Narada (although we only have proof that they were monitoring Robau's lifesigns). But nothing discussed there indicated the origin of the attackers! At the very best, our valiant sidekicks might decide that these people were renegade Vulcans of some sort, but they probably wouldn't make the connection to the old war with the faceless enemy.
I think the language contained in the logs would be enough. Not everyone in Starfleet's linguistics division is as ignorant of Romulan as Uhura's predecessor. While the "sidekicks" might not make the connection, higher ups at Starfleet Command, Starfleet Intelligence and the Vulcan government would. Indeed they must have, since Kirk, who only knows about it from either history and/or first person accounts, refers to the ship that attacked the Kelvin as a Romulan one.