I always thought because the cast were middle aged and going beyond that Saavik was supposed to add some youth and a good sight for the eyes. Same goes with David. They never did expand on that though really on TSFS. Maybe if negotiations failed with the original cast they had backups? I always prefer the extended cuts. The directors cut is 99.9% the same as the abctv version, save for a few alternate takes. Love the extra character moments. It adds about 4 min. To the film. I remember growing up my next door neighbor had taped the abctv version. We watched it like wow its like watching a whole new movie lol. Basically just pick up the 2 disc directors edition of TWOK on dvd.