Of course we should have seen this coming you know.
Wada realized Square was fucked with what XIII turned into.
The decree was handed down to shorten dev cycles on mainline FF games / major games in general. 2 years or so for big games. But there was no way they could about face to plan and execute the next actual Final Fantasy game on a dime.
So instead they've been sticking to the letter of the law by quickly assembling stuff out of the bones and assets of FF XIII. Wasn't there a suspicion that much of FF XIII-2 was made out of environments made for XIII but never used?
For this game, they probably did have to make wholly original content, but it's Square. No way they could make assets too elaborate in such a short timeframe. We've seen no indication that their internal development environment has changed or even started to change.
I think, if you want to hold out any hope for Square moving forward, this is your only scenario: while a relatively small crew worked on XIII-2 and XIII-3, others have been planning and prototyping Final Fantasy 15, in preparation for full production as soon as XIII-3 is out the door.