My personal prediction is between February and April. That's when Square Enix loves to release numbered chapters of the series in the west, and it makes sense with the current beta schedule. It could be SLIGHTLY earlier if SE wants to rush out (but not by much, I don't think it's realistic to predict a release anywhere before the end of january). or later if they want to take their time, but that window is the one that makes the most sense in the current conditions.