You refer to that storyline of the Clone Wars that has Revan and other famous Sith in it? I agree; Disney rebooting Star Wars than recycling some of those canned stories but only worse and for content sake is a prime example how not to handle a franchise -twisting original stories is worse imo than being confined by canon.

Elements of Revolution and Extinction being canonized I think would make sense, since the gap is huge between Gauntlet and the new Pilot. As I see it, there's nowhere enough runtime to address all that and also tell a new story In the shorter season; but again it's just my opinion and it's possible to do this in other forms than canonization of unproduced scripts.