Closest thing in that thread seems to be [Versu][1], which still wants to impute a great deal of detail into its working model.
My conception would be more of a history of previous actions, informing options presented to the players to flesh out, within the framework of archetypal story development.
I think this would mean some capability on behalf of the system, or perhaps the GM, to model the developments of the story tellers into the story-model so that relevant options are presented.
CYOA would essentially, if I remember correctly, present you with situational choices like go left or right and battles which you would conduct with die rolls and score accordingly.
My proposal would be closer to the bare bones of a CYOA novel, hiding the potential developments from the players (in the unread pages of the book, to keep with the analogy) whilst presenting some kind of gamified story telling option to the players.
The real problem seems to be how you would then insert the story developments in to the engine so that recognisable and sane story developments were presented.
Or perhaps a given result would be required, 'You attempt to bargain with your captor, you fail. How do you proceed?"
“I slay as many as I can before I am cut down and stand as an example of heroism to my people in the hope that they will take heed of my actions and rise up against this scourge.”
Result: Character dies, NPCs die, future characters of Players tribe are bolstered with +5 belief in themselves, 5% less chance of being ambushed. Reset character arc, begin new story thread.
or something.
The more I think about this the more difficult it seems.
Probably making the engine as absolutely simple as possible and having a GM pre-flesh-out options would make more sense but then, why bother with the engine at all? Gah.
[1]: http://versu.com/