Even if he had chosen to demand answers, it's very unlikely that Xemnas would have offered them. He has always tended to half-answers at best, and having things demanded of him is not really the best way to make him inclined to offer even that much.

(Which is not to say that Even can't try, but it isn't likely to help matters much in the long run.)

"Perhaps it is meant to be a mystery, then," he offers, with a smile that is really not likely to be comforting. All he knows for certain is that this isn't where he was, and that it is not entirely where he wants to be. But no matter. He will continue on as he always has, and that will do.