Ehhh it doesn't seem there actually was added any story guys.
I had a save before the final content fight with Van and the 'Sorry this is the end of the beta' message is still there directly after.
Also, it's not actually stated in the changelog that additional story content has been added...
Fix 449 - A new full scene has been added and can be triggered by doing something "usual" in Castle Warrengard.
I found this one. You have to sleep in your bed, BUT the variable 'Kythie Permanent' needs to be 3 or above. And mine isn't FOR SOME REASON. I suspect the variable additions or the variable itself was added long after my save. So the scene would require me to restart the playthrough again.
I've only been able to find a single +1 to the variable on the initial dialogue of party member Kythie.