User blog comment:Jkphantom9/Kerry's status on RWBY Volume 3/@comment-11188061-20150527044415/@comment-4010415-20150527051708

3 episode scripts written means there's a loooooooong way to go. So, unless those Reddit users are willing to be patient like some of us, it's gonna be a grueling wait.

They can't finish animating an episode if there's no script for it yet because they have to animate the characters saying their lines, both the lip synching and the body language. But they can't do that until the voice actors have voiced their lines, which involves doing multiple takes of each and every single line that they have, so the crew can pick which takes sound the best. And the voice actors can't voice their lines if there's no script.