Disney economics is based around the idea of "perceived value". It’s a game between how much value you think you get for your admission price, and how much money Disney wants to spend giving it to you.
Disney has decided that a “full day” is when you see 9 to 12 attractions. Anything less than that and you will feel that you didn’t see enough to justify the price of a ticket. And anything more than that is “extra value”, meaning you’d be happy without it.
So Disney’s goal is to only operate enough attractions to make sure most people get their 9-to-12. Each ride costs money to operate, yet you pay the same amount if you ride one attraction or thirty. Disney doesn’t get any benefit from ride number 13, you’d be happy not having ridden the thing yet it costs Disney bucks to run.
At a park a huge as EPCOT Center (the wand’s down, time to go back to the park’s real name too) has lots and lots of attractions – rides, shows, films, exhibits…plenty of places for your 9-to-12. Naturally, Disney is going to steer you to the cheapest to operate, highest capacity attractions it has. That means attractions with sponsors (who pick-up the operating costs of the attractions) or the ones inherently cheap per person (a movie theater holds a lot of people yet only needs a couple people to run the entire show).
‘Wonders of Life’ lost its sponsorship and became, in Disney’s fetid mind, too expensive to operate. ‘Body Wars’ is high on maintenance, the dome overall costs a lot just for lights and air conditioning. There are also lots of other places to fill your quota – so no one is going to feel “less value” because a whole pavilion is closed. In Disney’s mind, wandering through the museum space in Japan is just as “value” as watching ‘Cranium Command’.
So don’t look for anything there until the building gets a sponsor or a whole lot of other rides are shut down. Remember – seeing more than 12 attractions in a day is just the same stealing money from Disney.