I don't quite see how "Korea probably wouldn't be playable" in the possible expansion pack design.
I don't understand your point. Maybe you and I are thinking in very different perspectives.
There is nothing set for the possible expansion pack design, right? And-
if there had been any plans for the Imjin expansion pack, which there haven't, or not necessarily, or I'm not at to say whether there have, there would have been a project team which, had it existed, on which I cannot comment, would now have been disbanded, if it had existed, and the members returned to their original departments, if indeed there had been any such members.
Or, are you one of such members?