It's not that the areas exist but aren't enabled in the data. No zone and monster data exists, and no NPC dialogue. They'd have to create all of those and then add them to the game, and it requires their PS2 development environment to do so, which that equipment is down to very few working machines still. They've named the continents/kingdoms and given general directions to them, but nothing more has been designed, and so doesn't exist. It's not there to unlock, and the resources to create them are not up to the task. FFXI mobile may release and visit those areas, if it lasts long enough. For current FFXI, there's no way with the current situation that we will get that. The last major version update has come and gone, and it's too late to do anything else of that scale.