*ignores second video and all comments afterwards*
Recalling from Darth Bane: Path of Destruction,
Bane admired Revan, even if Revan was ultimately redeemed to the light side.
Of course this was written in 2006, and TOR was only in its conceptual stage, if that, so presumably it was referring to the light side ending of KOTOR. I theorized whatever the case was if they were bringing Revan back in some form, it would have to end up being light sided to not contradict canon.
So I theorize further that if there are dark alternates that could be considered also canon:
1) Revan will be killed by you but remain light side.
2) Revan is consumed by the dark side and joins you. In killing the emperor he succeeds if you allow it.
3) OR any variation of the above PROVIDED THAT Revan is NOT known to the galaxy at large to still live.