The film wants us to assume he knew they were Romulans from appearance, that they always looked like that.
Those are two completely separate things. "They always looked like that" is the default setting, and the movie doesn't want to shake default - indeed, it wants us to think that there's nothing new there before 2233 (even though we can tell this is not quite true, as "their" 23rd century has production values differing from those of "earlier" 23rd century).
But keeping the default setting is in no way dependent on the heroes of 2233 recognizing the Romulans. And indeed we see no signs of recognition when we see 2233.
Wait? Pike didn't know they were Romulans? Since when?
The question apparently is "until when?" instead, as he shouldn't have known in 2233 yet. That's in the rules of Star Trek, and nothing about the movie broke those rules, so the burden of proof would be on showing that "Romulans" would be a factor in 2233 already.
I mean, the lightning storm connection seems kind of silly that he didn't know, but there was no sign of the Narada when Spock returned, vs what the Kelvin encountered, so I give a small pass.
That Chekov in his PA is even mentioning the space storm is extremely odd - what does
that have to do with anything, least of all seismic trouble on Vulcan? It very much looks as if Pike is telling him to mention the space storm. But those space storms have only one known consequence - the emergence of giant Romulan vessels. Is Pike disassociating the storm with Romulan superships, or just with Romulans? He seems opposed to the idea that Romulans would be involved, but also to the idea that a ship would be involved, so it could go either way. But either way, he's a fool.
Number two, why is Pike a fool? Such harsh language for no apparent reason.
He's the Federation expert on what's happening on Vulcan. Why is he being upstaged by a cadet? The fool was about to kill the thousands aboard his ship and under his command.
Not that Kirk's intervention did anything much. Raising the shields did not protect the ship from an immediate ambush - the debris field protected the ship from an immediate ambush, delaying Nero's reaction so that Pike could see the threat first and order shields raised in any case. In essence, it was Sulu's lack of piloting skill that saved the ship, by making the
Enterprise late for the massacre...
(We could speculate, though, that Kirk's rantings made Sulu extra careful in entering Vulcan orbit and avoided a worse collision - and/or that raising shields when you have cadets for crew is slow business, and Pike couldn't have done it in time if merely spotting Nero's ship when he did.)
Timo Saloniemi