Though im sure they can find any way to bring him back. Maybe he was held in a stasis field for that long, maybe someone found his resting place and got him back, idk... But first we gotta know how will they end his story in TOR timeline.
(maybe this TOR expansion is another hint
They got the plot from the film guys and will wrap Revan's story up, so he can be revived/returned from sleep/rescued from a stasis field/etc/etc in the new film)i might be horribly mistaken but from what i know Sidious master, Darth Plagueis (he mentions him while he's talking to Anakin) was the one able to "cheat death" and do those things with the midchlorians and etc. Sidious and Plagueis planned the whole thing, the civil war, the clone army, and Anakin, so they could end up controling the galaxy through mostly "political means" (but with a hell of using the force to conceal themselves from the jedi and influencing whoever needed to be influenced). So Plagueis knew how to do it, Sidious was his apprentice and knew about it but didnt learn himself. (or Sidious did knew the power but played Anakin and let Padme die)Jorel well what do you not know is in Epic 3 Sidious told this to Anakin To cheat death is a power only one has achieved through centuries of the study of the Force. But if we work together, I know we can discover the secret to eternal life so who is this ONE that have been cheat death it give more meaning there 2 order of the force Sith or Jedi but how in the nine hell do the Sidious know about this and where do he know of it
I think it will be amazing.