According to cast members who work at Epcot’s Universe of Energy, they have been informed by managers of a closing date for the Ellen’s Energy Adventure attraction.
If the cast members are to be believed, the attraction will shutter in January 2017 to make way for the rumored Guardians of the Galaxy roller coaster attraction. The Guardians of the Galaxy ride is likely to be announced at the upcoming Destination D event by Bob Chapek according to internal rumblings at the company.
The Guardians of the Galaxy ride for Epcot was originally slated to be announced at Comic Con alongside the Mission: Breakout attraction replacing Tower of Terror at Disney California Adventure. It seems as though the Epcot ride was simply not completely “green-lit” in time to make the announcement a dual one.
Do keep in mind that much of what you read above is still in the realm of rumor at this time (as is anything until finally confirmed by the Walt Disney Company), but with the rumblings growing stronger and stronger each day, it is seeming more and more likely to become a reality.