According to a Tweet made by Square Enix’s official Twitter page, the reveal made by Goofy’s voice actor, Bill Farmer, that Kingdom Hearts III would be releasing later this year proved to be unconfirmed.
There was a Goof! The release date for @KINGDOMHEARTS III remains unannounced.
— SQUARE ENIX USA (@SquareEnixUSA) January 8, 2015
While this doesn’t necessarily mean that the game won’t come out this year, it just means that Square Enix is hesitant about making any announcement on either side of the subject.