From what I read on http://www.disneyfanatic.com/7-sensational-facts-world-showcase/, Disney actually only got funding from Norway and Morocco. In fact, one of my favorite Disney facts is that the king of Morocco was so excited that there would be a pavilion representing his country, he sent his own team to construct the intricate architecture.Unless I'm mistaken, my understanding is that the pavillions in Epcot were funded by the countries they represent.
Therefore, the issue is finding a country that's:
A)willing to put up the money
And
B)not controversial
What really gets me is that, unless there is some political barrier, Disney has the money to add a new pavilion. They spent approximately $100 million on a yeti ride that doesn't even have a working yeti audio-animatronic (#disneysmostexpensivestatue #discoyeti). So it seems like they have the financial means to make this happen!