In the latest issue of Dengeki Playstation, 'Kingdom Hearts' director, Tetsuya Nomura, talked a bit on both 'Kingdom Hearts 2.8 HD Final Chapter Prologue' and 'Kingdom Hearts III'. While a full translation of the interview isn't out yet, KHInsider user Zephyr was able to translate some of the main points of the interview, where Nomura discusses things such as no new boxart for 'Kingdom Hearts 1.5+2.5' on the PS4, how the remasters have never affected development of KH3, and the return of Reaction Commands in KH3 (now called Situation Commands and evolved to be less like simple QTEs). The main points can be read below:
This post will be updated with the full interview as soon as a translation is out.
EDIT: The full interview is as follows (thanks again to KHInsider for providing the translation)
Nomura Interview with Dengeki (UPDATED with Full Translated Interview)