There's 4 more areas from 1.0 not present on the list: West Shroud (which I guess we're never seeing again), Coerthas Eastern Highlands, CE Lowlands and Coerthas Central Lowlands (which should be between Mor Dhona and Central Highlands, but we're just skipping it now). If two parts of Ishgard are counted as 2 different zones on the list, that'd be extremely cheap, but they probably are.

So counting Ishgard as two zones and adding Floating Continent to the list we have just one zone they haven't revealed yet which could be either because Floating Continent is also two zones, or the last one is a big spoiler. Obviously Eastern Coerthas can be neither.