When the Frozen overlay first hit our boards, I spent a significant amount of time discussing the direction with fellow Disney Parks & Resorts fans. Our conversations regularly transitioned from Epcot to themed entertainment, including aquariums, museums, and zoos. Although some museums have permanent collections, many have rotating, temporary, traveling, and/or visiting exhibits. Rotation piques interest and boosts attendance. Galleries may change, but the mission statement of the museum remains the same. Generally, contemporary art museums with successful 30+ year histories do not suddenly begin showcasing baroque art in their 35th year.
Like Disneyland Park and Magic Kingdom, I believe Epcot needs a permanent collection (i.e., classic attractions). Nostalgia and sentiment aside, the American Adventure and Spaceship Earth are the lifeblood of World Showcase and Future World, respectively. All of the countries surrounding World Showcase Lagoon and the other pavilions in Future World would benefit from rotation. However, the rotation should be guided by the mission statement. Parks & Resorts should bring change to Epcot, but change that continues to inspire interest in new knowledge from science and understanding between nations. Test Track and Soarin' demonstrative that automotive engineering and topography, respectively, can be cool.