Remember that suspicious Korean puzzle in Surgeon Simulator 2013—which people assumed teased a Valve product? The developers say it's an ARG, but it's unrelated to Valve or Half-Life.
So an indie developer just happened to start an ARG in their Valve game themed expansion, with a clue in Korean, a week after Valve put out a 'bugged' HL2 update that stuck the game in Korean, and they aren't related. Sounds totally legit guys.
The alternative that it's exactly what the SS guys say it is, unrelated to Valve, and they purposely choose to go the Korean route, in Valve related content, to take advantage of the existing recent Valve speculation to fuel interest in their ARG, kinda makes them manipulative jerks, no? I can't believe there's really a third alternative where they didn't even realize the Korean might fuel Valve speculation given recent events and it was chosen arbitrarily.