Of course, the easiest and possibly best thing to do would be to set it after Legacy: War
. They could start fresh with a new (at least to the film world) crop of characters, with freedom to do whatever the heck they wanted without damaging existing EU continuity. As a bonus, the era in question is set up perfectly for an old-school story setup: No alien weirdness here, just the main characters, a galactic government doomed to fail/fracture somehow
, and a group of Sith that prefer to work undercover.
Alas, it seems it's too late for this.