@kugel-
It's not even clear to me if this is even a bug (as in "not working as intended"). I surely never used that pref.
Well, to me it's definitely a bug as the session is *not* restored as it was saved. Both documents order and current document are lost (well, current document is OK if it's the first one -- and that's likely why I didn't notice very often as I usually have the same doc I come back to a lot as the first one).
And having added the feature back then, I can tell you I didn't plan for this :)