BioWare ignored TSL...
So why can't Obsidian make KotOR III and ignore BioWare? And BioWare did ignore Obsidian. They made it that the emperor turned Revan to the dark side, ignoring the fact that Revan left the infrastructure of the Republic intact and waged a war of conversion, not destruction.
I think if Obsidian ever made KotOR III, they should ignore the novel and the MMO. Make the game about searching for whatever it was that lead Revan to the true Sith in the first place. Find the true Sith and help Revan and the Exile defeat them for good. The end.