I disagree. If a DLC isn't going to be part of the core game, and possibly even expanded upon in future DLCs, then why make it?
For me personally, WoL was already a departure enough from everyday medieval life. If they're going to make another role-playing DLC I'd like it to be at least somewhat historical. Which is why I like
@klopkr's idea of depicting myths and legends believed at the time, like the "Sword of Odin"or "White Stag" events you can get while hunting. The stigmata, voice of Jesus, and Jeanne d'Arc events are also good examples.
Now that I think about, that could be lumped in with a DLC that adds new religious mechanics for Jews and non-Abrahamic faiths.