I think the Foundry ends the way it does for the same reason:
It's a hackneyed, err, tried and true way of leaving the door open so to speak.
And to the play Devil's Advocate to the argument that neither Yoda nor Obi Wan left a body, but were still dead: in the EU both Sidious (Sidious even tells Anakin that those strong enough in the Dark Side can beat death) and Boba Fett return from almost certain death. And don't forget that the force ghosts of Yoda and Obi Wan are what "confirm" their deaths.
tl;dr: I think Revan fanboys are still totally justified in believing him to still be alive.