Its very likely that the games release is coming, as they are finally make a big deal about Disney worlds appearing in the game (and they wouldn't be showing them off like they did with Tangled this E3 if the game wasn't close to completion). My guess is that KH3 is either a fall 2016 World-Wide release or fall release in JP/spring release in NA/EU.
Regarding FFXV, that is at this point 70-80% complete, so now they are just polishing the combat engine, leveling systems and taking peoples feedback from the PS4/X1 Demo that came with Typo-0 and integrating that feedback into the final game. The only issue that team is facing is ensuring a stable frame-rate for the tittle, as if the 2.0 Demo is any indication, they are making great progress on PS4 but need a lot of work for the X1 (as that goes into the 10's with Frame Rate if DF is correct). The game basically needs some refinement for the remainder of the year, that way it can be ready for launch in JP either this fall or early this spring. Than localization can start, leading it to launch in NA/EU summer 2016/fall 2016 (and that pushes KH3 into early 2017).
Dragon Quest XI is likely a cross-generation game, so that should come out much faster than both KH3 and FFXV combined. So, with that in mind, I feel that it will launch sometime in 2017 after KH3's release or be held-off until FFVII Remake comes out.
Speaking of the FFVII Remake, that is using both Unreal Engine 4 and is a huge tittle for Square Enix for pushing PS4's in JP, so they must want the game out very soon. And if the rumors were right, the game has been in the works for a good year before this E3's announcement; solid work has been done so far on the tittle. So, a late 2017 or early 2018 release is likely.
Square, to put it bluntly, got there shit together with the PS4. Its easy for them to work with, they have UE4 to work with and they understand HD development now. That alongside learning a lot from their partnership with Edios and the work they did with their tittles, they understand HD development better than most JP studios on the market now.
I have high hopes with Square Enix thanks to this E3, so lets see what happens
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