Ditto on the preface that people have a right to feel disappointed or not, etc...
Everyone has different reasons for how they plan their trips. We're a family that visits once every year or two...For me, the main reasons that I have made PPO ADRs is to (1) eat in the restaurant and (2) not waste valuable morning touring time in the restaurant. Since I've been able to book the reservation before the park opens, I think that while not promised, at the time of booking I have been able to meet these two goals, since the reservation has been booked for a time that park is not open (not to sound too redundant). Other perks, when it's happened, have been a bonus. When the hours change, and I anticipate that they will, I am disappointed not because I feel like I was promised some type of non-explicit perk, but because now I am no longer meeting my second goal and I have to make a choice whether to waste that valuable morning time in a restaurant, which generally I don't since we don't get there that frequently. Then I'm disappointed that it's tough to reschedule that ADR for a better time, given that it's usually later in the game, although that's what we did last year. However, I know this is how it works and there are not guarantees, so I just roll with it. Our next trip, we're planning lunches instead of breakfasts for a mid-day break, but just speaking to past experiences...
Having said that, I'm looking forward to this change (although I will miss the train show), and I'm interested to see how it works for EMH mornings! I am also interested in morning pastries...