Also, the Romulan language has been known since before the UFP was formed. T'Pol knew the language in the 22nd Century and Hoshi Sato heard it then.
But STXI insists that it's indistinguishable from Vulcan, unless you are an expert. Something really doesn't add up there.
In terms of the nuMovies, the first Nero encounter would offer zero information on why this bunch of violent Vulcanoids attacked a Starfleet ship. In terms of the rest of Trek, Romulans must have changed their native language after "Minefield"!
I guess the only way out of this is to assume that when the no-name Lieutenant indicates inability to tell Romulan from Vulcan, it's akin to somebody saying he can't tell Polish from Russian. This is only halfway plausible: Romulans are such an ancient enemy that it's perfectly possible virtually nobody knows their language - but Vulcans are such a close ally that any communications officer should be fluent in that language, or at least be able to positively identify it.
Okay, let's believe that one impossibility before breakfast: perhaps nobody bothers to learn Vulcan, because there are fewer than 10,000 Vulcans outside the homeworld. Fine; nuUhura is a linguist, and knows both of the obscure languages. Pike probably had experts to help him establish for his dissertation that Nero spoke Romulan - but now we hit the next problem...
...He doesn't see any connection between the space thunderstorm (an odd phenomenon Chekov deems worth reporting, wholly out of context!) and Romulans, despite being the expert there! How does that fit with the supposed timelines? Are space thunderstorms fairly typical after all, even though none were encountered before 2233? Or is Pike simply far less interested in his old dissertation than the obsessed Kirk Jr.? (Perhaps he copy-pasted his academic work?)