Although bits and pieces of this information has slowly been revealed over the last four or so years, I don't think the importance of this can be understated. I truly believe this is the largest most significant announcement/innovation in the theme park industry ever.
The last decade has seen a focus on the idea of immersion, what Disney is talking about is not immersion, it is inhabitation. The Wizarding World of Harry Potter may have incredible themeing, and a few elements may even be interactive, but those interactions are all binary and part of a largely linear story.
If WWoHP is like a movie then the new star wars experience (as described) is closer to an expansive open video game. The "Story Engine" is in reality a Game Engine. This is the promise of magic bands and
MDE. We are not talking about a princess knowing your favorite color or a hitchhiking ghost knowing where you came from. We are talking about a world that will respond to you and the decision you make and your decision history in real time. (again, concepts burrowed from gaming tech).
I am sure that the SWE will not be a full realization of these concepts, but it will be a massive step forward in a direction no-one has ever gone before, at least not on this scale
For those that thought MagicBands were just a virtual queuing system or a convenience tool for guests, this proves otherwise. They are an integral part of this new vision of interactive guest driven story telling. They are the memory packs in Disney's new video game-esque theme park world. they connect each guest to the "story engine" and save all of the user information needed for the story engine to propel this new free-form open ended experience into new and unique directions for each guest.
This is far beyond any new ride system, or benchmark in themeing. This is an ambitious visionary revolution. A disruptive technological breakthrough, that, if realized, will forever change the way guests experience not just individual attractions, but entire parks.
I also think it is important to note that this has been a very long play on Disney's part. The team has been doing research and development in both technology and guest experience and participation for nearly a decade to create this. Perhaps it is time to cut them a little slack. They have clearly been busy working on a brave new world while many just assumed they were asleep at the switch.