Thinking out loud here … "Why do a dry run on the holidays?" MOST of the events hitting the news have been related to air travel. Air travel picks way, way up during the holidays. If that's what it was, then the point was to do this dry run during a time of peak traffic. Frankly that doesn't make much sense for any number of reasons.
Maybe the Bannon thing was to gauge public reaction to a "falling out" involving Trump and somebody else. Bannon has a cult following at best; not too big but big enough to be potentially useful for seeing what comes of it. It's doubtful that the response of the media would have been examined because that's more or less a constant and there is little that could be taken from a dry run that wasn't already obvious.
Maybe it's about key Republicans going down, but entering that area, it all seems to move toward grasping at straws. It's probably something more conrcete.