Disney is setting a dangerous precedent with that stunt. Guests will hold it over there head when a attraction breaks down on its grand opening, and since people use Disney as the paragon of integrity for the other Orlando local parks. All this is going to do is empower guests to be more entitled when it comes to down times and opening day malfunctions.
Let's look at it from this standpoint. People bought tickets solely for today, If they were in a boarding group and didn't get on, the got a FREE ticket. The signs they had in the park, one the printed handout for the boarding passes and the boarding pass segment of the application said they can't guarantee you will experience the attraction.
Let's see how well this will blow up next time...