Hasn't this really been the story of 2016, low attendance? This has nothing to do with congestion pricing, it has everything to do with the parks either being half closed, people getting Disney fatigue, too expensive, or people just don't want to be bothered with the hassle of paying top rates to be herded together in the parks. I would tend to discount the latter, because most people know Disney is still busy during the holidays.
Don't think for a second that execs are not concerned about this. The holiday season is an important barometer for how things are going, the fact that there has not been a single phase closing yet, (even during Thanksgiving) should be VERY concerning short term. I think the closest that we got to a capacity closing was the parking lot at EPCOT closed during one of the last days of F+W.
So I guess until SWL and TSL open in a couple of years, which will probably bring more attendance in, expect to see more up-charge events, more parties, more gimmicks and trials to try to appeal to high margin guests. But if you're in the upper income category, are you really going to be a Disney World customer?