I've seen this question before. I mean no offense in saying this (I have computers, phones and tablets myself that I love), but it's somewhat short sighted to think Disney would be unable to "keep up" based solely on these devices.
EPCOT's glimpses into the future were far more grand. Certainly there were areas such as Communicore and Innoventions that focused on more everyday leaps in technology. But the larger scale attractions handled future prediction on another level entirely, the focus was on much bigger and more ambitious things than cellphones or computers. Horizons had scenes depicting underwater cities and space colonies, which are still largely out of reach (even for the very rich, let alone for the average person). Any updates required would have actually been more aesthetic than conceptual, not that hard to imagine Horizons existing in this day and age had it just been given some minor tweaks over the years.
There was actually generally a greater emphasis on looking into the past than the future. The vast majority of Spaceship Earth covers ancient history, moreso than anything futuristic. Same goes for World of Motion. Only the last couple of scenes (which are easily changed without replacing the rest of the ride) depicted anything remotely futuristic. Even the first half of Horizons is dedicated to how people from the early 1900's into the mid 1900's thought the future would turn out (all these scenes would require no changes whatsoever). Imagination was never about future prediction, it was about how the mind takes "sparks" of abstract thought and uses them to.
While i'm sure the creators didn't intend for the rides themselves to be gutted and replaced entirely, they did intend certain aspects of the park to be continually updated (particularly Communicore and Innoventions). Spaceship Earth was one example that was updated multiple times, it is on its fourth version now. Horizons was also intended to get a similar upgrade before a new sponsor arrived and mandated a different attraction. Many attractions didn't need much updating at all, just occasional upgrades to projectors or animatronic or whatever.