I'm just saying I can take my copy of X, which I've been playing on my Fire Emblem 3DS, and insert it into my launch 3DS, and resume my game. Likewise, I can take my copy of Y, which I've been playing on my launch 3DS, insert it into my Fire Emblem 3DS, and resume my game.
My point is that it may not be so reliant on the 3DS hardware/firmware as was previously speculated. Unless I'm misunderstanding what was said, which is entirely possible.