I think that IF (and emphasis on if here) Z isn't happening this year, it'll be because plans changed, not because they never planned to do it in the first place.
If, for example, Game Freak decided to make a concerted effort to get onto Nintendo's next console as early as possible this time in order to establish a foothold on the platform before any pressing competition *coughYokaiWatchcough* could make the jump, and were then told that Nintendo were pressing forward with the plans for the NX earlier than they initially intended, I could imagine them sacrificing Z in order to ensure that they are able to turn more resources towards getting the next generation out as soon as possible, leaving them with a variety of formes that they have to give an anime arc to in the absence of them getting their own game.
Hey, it's all just speculation, but that's the fun of it!