Might it be that we see these arcs explored another way? In comic book form etc?
The video below from Filoni shows a fully animated and voiced clip, so obviously at least some of them will be in the same type of animation as the series proper. If it's not moving to Disney XD, then I wouldn't be surprised if it was done as either web series or direct to video/download type thing.
I'm really curious what new era the new series will be set in. Someone up thread mentioned the era between ROTJ and VII, and that does seem like the most likely setting to me. That or between the first two trilogies or pre-Prequels.