IMO what we have here is the potential for loyal Disneygoers to create new habits. However brief it may be in relative terms, there's going to be a period of time where rates have gone up significantly while the number of available attractions and quality of those attractions have somewhat decreased.
You're hearing a lot of people who might not otherwise consider going to Universal very often – myself included – considering a trip to universal in this perceived "off period" for Disney.
In the long run, that sets up the potential for more people to like what they see at Universal, and to plan future trips split between the two instead of spending a full vacation at Walt Disney World. I realize some people already do this, I'm suggesting it may happen in greater numbers because of the way things are lining up over the next two to four years.
Even if people come back for Star Wars, which I'm sure they will in droves, they will have potentially established other vacation patterns and loyalties/favorites by that time.
It's very similar to what happened years ago between eBay and Amazon. Ebay got arrogant and raised fees to the point of diminishing returns for many sellers. Those sellers, who may never have considered selling on Amazon before, suddenly decided to start selling on Amazon. To this day, many of those sellers either never returned to Ebay or returned with a much smaller footprint. Of course Ebay didn't go out of business and neither will Disney – but their competitors can become stronger and more viable during periods like this.