Even more so, as if their secret weren't transparent enough, game will spoil those during character creation due to the origin system (and loading screens give up some reveals as well).

Again origins are here to blame. I remember sometime during D:OS2 production Larian saying how D:OS2 coop will not always be coop with players pursuing different, conflicting objectives. While something of that sort exists, it is very underplayed. Those open secrets seem like leftovers from this concept.