The aim has to be PS4 holiday 2017 for the 20th anniversary.
-Two more solid years of development.
-Should have the full attention of CyberConnect2 (which has hired for a massive scale, AAA production already), with assistance from Square-Enix Japan and
possibly SCE-WW Studios (if speculation is to be believed). The latter might even ramp up budget and development support after the gigaton bomb that was dropped on the internet last night. This could turn out to be a gigantic production team.
-FFXV has a new production management staff, KH3 appears to be in good hands, so Nomura should be able to put the majority of his concentration in this. Same with Kitase, as Mevius FF has released.
-UE4 appears to be development friendly to work with (so no more dicking around with confusing proprietary engines), so potentially more of a smooth, streamlined development?
-Safe to assume at this point a script has been created and a development outline is set. This is especially the case if Verendus was accurate regarding foundation for this being set as far back as 2013.
There is a ton of cynicism for this project completing and releasing in any kind of reasonable time around here- and for good reason. Look no further than FFvsXIII/FFXV. However, S-E has changed since all of that mess. As easily as you can look at the Versus/XV debacle, also look at the FFXIV recovery. That turn around was miraculous- and ARR is damn near a completely new game compared to XIV Vanilla.
Versus has essentially been remade from the ground-up. S-E was able to get a pretty hefty playable demo into retail for XV within 21 months of its E3 2013 reveal- and I think most of us expect the full game to hit retail within the next 18 months. By this point we all know how insanely ambitious FFXV is.
Call me crazy- I'll immediately accept it- but I don't think it's an impossibility to see this FFVII Remake drop before the end of 2017.
It won't surprise me if it falls to 2018, but I have to believe S-E is comfortable in the production of this to show it off in 2015.