Ok so I am going to piece together what I know about the current events in the game that lead to FFXIV v2.0. (Spoiler Ahead)

We gain the power of the Echo, which we see the past of Moh Dhona, and the Shinryu-type dragon. We pick a city which leads us to Ul'dah where we find out more about the beast tribes, and their fear of the ascians.

Urianger appears a few months later to talk about the coming of the 7th Umbral Era. The Garlean Empire starts attacking us again after a 20 year halt in there attack. It's starts raining alot in Gridania. The moon is now larger and red. Cid talks about meteor. The Grand Companies start, to fight the Empire.

We hear from Cid, Urianger, Y'shtola, Thancred, Papalymo, and that companion of his, that Empire is not the threat. Legatus Darnus wants to destroy the Primals which are sucking up Aetherytical energy, to save the planet.

Me putting it together in my own way:

Someone is controlling the lesser moon to the planet. It's going to hit us. Why? Look at Ifrit. What happened when Darnus destroyed the Aetheryte Node. All that energy went into Ifrit making him even more powerful.

That moon is going to hit us, it'll cause a massive tectonic movement which will lead to the new zone redesigns. All that Aetheryte energy is going to be dangling around for someone to grab. Namely monsters, which will cause giants, chimeras, and others to appear.

That Ascian that appeared in the Lord Errant mission, maybe seeking that Aetheryte energy to revive that dragon.