I always say it, but Millenium Epcot was awful aside from IROE and Tapestry. While this overhaul is *interesting*, it's not bad. The millenium was much more destructive of original Epcot than this.
They literally demolished half of the park's central organizing principle for the current project, but the elements that they added during the Millennium Celebration were more destructive? I'm not sure I follow that logic.
Sure, the Millennium-era stuff was a product of its time, a lot of visual clutter was added, and the finishes tended to be more industrial than luxurious, but ultimately relatively little of it actually detracted from the park's existing experiences themselves. The park's central plaza remained a plaza (with the shade and kinetics of trees and water swapped for canopies and whirligigs), the nighttime lagoon show remained a high-tech salute to global cultures, and Spaceship Earth remained unchanged as an attraction. The infrastructure improvements made to the World Showcase promenade for nightly parades and the Reflections of Earth torches remain in regular use to this day, despite their original shows having been retired.
[It should be noted that although the Imagination redo was tied into the Millennium Celebration for marketing purposes, it wasn't really connected from a design or budget perspective, the timing just worked out nicely; a similar tie-in happened with Indiana Jones for DL's 40th]
Additionally, it's tough to argue that the additions were somehow destructive to the park thematically. The then-new technologies on showcase in Innoventions, the multicultural celebration of the Millennium Village, and global focus of Tapestry of Nations and Reflections of Earth all fit the park's mission like a glove. Arguably, it was the last time the park really went all-in on the original ideas of showcasing human achievement. The park has drifted away from those ideals in the intervening years, but the pace increased rapidly with the park overhaul project.
And while many of the elements overstayed their welcome, they were always designed to be temporary. Nearly everything was added on top of the existing infrastructure: although the aesthetics changed, the basic framework of how guests interacted with them remained the same. There was very little intention that any of it would redefine the park for generations to come; it was an ephemeral moment in time, rather than monumental construction meant to be a draw for years to come.
Contrast that with the current project, which has demolished half of the park's spacial organizing structure, removed several facilities without meaningful replacement, added a massive unthemed warehouse to the horizon, tries to reinvent the park's mission, and is very much intended to be a permanent fix to the park's woes. While I can see how Epcot's Millennium-era additions don't meaningfully connect to audiences in 2022, I don't see how it was somehow more destructive to the park than what they're doing now.
Temporary additions will never be as destructive as permanent demolition and headliner construction.