My guess would be in September; maybe early October. I think that's doable for a game that seems in the final stages of development, guess we'll know more soon.
For those who like walls of text here's some facts summed up:
- The game was playable start to finish in November; with the first half of the game polished, and most but not all features implemented (pre-beta)
- Next up they're working on the beta version (ie all content/features finalized and only bugs left)
- At Gamescom last year (August) Tabata said all environments of the game were about 70%/80% done and lacking finish.
- While Square has done more talking than showing, it sounds like development is advancing well along and they know what they're doing, so I'm not expecting any major changes from the gameplay we'll see in the ATR later this month. Or cases of "oh chocobo this totally does not work and will have to be changed" when they finally play through the full game.
- The game has to go through localisation (and there will be a ton of text), age ratings and Sony/Microsoft certification. This can be time consuming, but I imagine the team has decent experience with this so I'm giving them the upper hand and guess this won't be much of an issue.
- They will likely lose some development time from the preparations of a new demo version and the March event; as well as other promotional efforts.
- Some parts of the game are outsourced; they need to get together. Also the Avalanche partnership.
Well to be honest I think it could be released in Summer (July/August) but they probably don't want to clash with games like Persona 5 and other big budget titles. I don't think Square can drop this to the market when it's done, this game is a big deal for them. The game has to be good and it has to perform from a financial point of view. If it's better to release it a little later, they'll go with that. They need the revenue, they've lost so much money on this game already.
I also don't think the Airship things will make it into the game. I'm quite certain Square's thinking about ways to increase the game's lifespan and lore, not by sequels but through DLC, maybe ingame microtransactions, a companion app, comics/short movies. This game is just big to them, has a lot of hype and I'm pretty certain they will do something with it.