What fans know so far about "Kingdom Hearts 3" is that it is eventually coming. At the moment the date is not yet definite but it has been slated for release sometime in 2016 and in the meantime, the developers keep building up fan excitement.
One evidence can be found in the recent interview with "Kingdom Hearts 3" Director Tetsuya Nomura in the Square Enix blog site. Clearly the segmental release of the conversation between Young Xehanort and Eraqus up to D3 when the scene was finally showcased in its entirety built so much excitement among fans. Speaking of which, Nomura has said that since Xehanort and Eraqus' conversation was for an opening scene a versatile piece, which will not conflict with whatever world the game might feature or not feature, it is a "great asset to use as a prologue to build up excitement towards KH3."
For fans, to know that the company is still working on a certain title is a great relief. However, it should be noted that based on that interview, it looks like "Kingdom Hearts 3" is nowhere near final development stages yet. Nomura has said, "The scenes that we currently have released is not the final product so please look forward to any changes that we may make in the future as well."
Could the Game Director be referring to the trailer shown at Jump Fiesta as well? According to Gaming Bolt, the new trailer for "Kingdom Hearts HD 2.8 Final Chapter Prologue" at the recent Jump Fiesta in Japan features scenes from "Kingdom Hearts 3." The 5-minute footage featured a gameplay from "Kingdom Hearts 3" at mark 3:40. Besides Sora, Goofy and Donald beating enemies throughout the remaining part of the footage a new ride attack, the Buzz Lightyear ride, was shown. Not much has been revealed but would it be safe to say that even those in that that short clip may be subject to change as well?
"Kingdom Hearts 3" is currently in development and will be released in 2016. It looks like "Kingdom Hearts 3" may have plenty of room for changes.