It was in the interviews with Orci arond the time the first USS Kelvin, she is said to have been part of the Earth-Romulan War. And if it wasn't it doesn't matter, I'll just delete a setence fro the class description.
When we first saw mention of the Kelvin
, the word was that it was
...a Federation starship from a generation before the Enterprise and smaller than the Enterprise. It is of a new ship class never seen before. The ship is commanded by Captain Robau (Faran Tahir) with George Kirk (Chris Hemsworth) as first officer. Locations seen on the ship include the bridge (which reflects an earlier design than the Enterprise and is a lot ‘busier’), corridors, sickbay and engineering.
Nothing I've seen indicates that it's anywhere near old enough to have figured in the Earth-Romulan War.
Which leaves us with the other question: what is this thread actually about? Is it about ship design? Is it about the artwork in the images? If it's simply about the ship becoming canon, that's easy: it's in the movie, and is canon on that basis already.