Samsara is the subset of Plot that includes all events that it serves Plot to have the Maidens know. No more, no less.
My pet theory is that Sacheverell discovered he was an NPC, not in the sense of knowing he's in a game, but in that he knows he is a supporting character in someone else's saga. Now he's stuck in a depressed coma because nothing he does matters.
And the fun part is that because he's in no state to share any of what he saw, the matter of predetermination remains a sublime mystery. He could see everything in samsara and all it would do is make him that much more miserable and alone.
But I'm mean like that.
Ultimately, the most important part of the samsara sidebar is the bit that talks about how you should never use it as an excuse to railroad unless you're setting up something even cooler for the player to do. In other words, it's not ok within the spirit of Exalted for the Storyteller to arbitrarily say "The bad guy knocks you out and drags you back to his dungeon where you wake up behind bars" without giving you a reasonable chance to prevent this turn of events. However, if the Storyteler captures your character by fiat, onlyto have you awaken in that jail cell, bust out and lead the prison break/uprising against the Evil Overlord, then suddenly we're back to playing Exalted right. Short-term deprotagonization for long-term (or higher-emotional-payoff) player-driven narrative is a good trade, provided the ST makes good on his end of the bargain. Developing the trust to take those plot detours and have players run with it greatly enhances the possibilities and richness of the story.
I am very, very firmly against anything that detracts from the centrality of Exalted protagonists within their own stories.
It is not useful to try to model how samsara would react to a being that could ignore it, as it is deliberately constructed so that no such being exists. The paradox is thereby largely avoided.