I wouldn't be surprised if the movie creative team had no involvement in the writing of the books (which I thought was outsourced to non-Disney writers, no?).
It wouldn't be the first time that Disney's demonstrated that their left hand has absolutely no idea what the right hand is doing - there've been several disconnects between the movie creative team and merchandising.

At any rate, be he "official" or not, I still prefer Kopa over Kiara.