The upgrades needed to keep Future World fresh are overblown. They're upgrades I would expect of any Disney park, stagnation harms all theme parks. Of the original Future World rides, the only ride that even needed substantial upgrades was Horizons. Arguably Universe of Energy needed help as well. Communicore just needed minor updating to remain fresh. There are plenty of new technologies that won't be available to the public for decades (graphene for instance).
Spaceship Earth was well cared for until 2007. Imagination 1.0 needed absolutely nothing and wasn't outdated. Same with World of Motion. Living Seas was better before Nemo, what it arguably could have used was a new ride (something more substantial than the seacabs, i've seen concept art of such a ride). Wonders of Life also didn't warrant a change or closure, though again a new ride addition would have been welcome. I still love Living with the Land, only the videos in the barn are really in need of updating.
Even Horizons wasn't as outdated as some claim. Residential space colonies and underwater cities are still just as exciting and futuristic as ever (and just as out of reach to the general public). Real flying cars aren't any closer to happening either. Even fiber optic communication. video phones and electric cars are in their infancy for public availability. Still decades out before they actually become common and widely available.
Much of the original EPCOT Center would have still been futuristic today. The changes that would have been needed were largely cosmetic in nature. What I mean by that for example- flying cars are still as futuristic, exciting and out of reach as ever. What has changed over the years are aesthetic car designs. Nothing that should warrant the loss of a classic and fantastic ride.
Minor visual plussing to ride scenes every 5 years or so isn't difficult or expensive.