The mindset is that they took a survey asking if they celebrated the 50th well enough. To their surprise (or maybe not), they received feedback that there was not enough emphasis on the history of WDW, Walt, nostalgia, etc. Now, the rest of us know that should have been obvious from the beginning. Better late than never. It's like "Welcome to the party, pal. Where have you been?" I think they intro will stay with this version of the fireworks through March of next year when the 50th celebration ends. What follows after? Who knows?