I guess with all pavilions, you need to cherry pick the bits of history that you want to present to the public - including the USA. Or you at least have to try to present the bad parts in the best way possible. For the USA, we have our own checkered past with slavery and continued prejudice against minorities. Disney has tried to address those issues, at least modestly, with the exhibits and main attraction. For Russia, you'd need to ignore the communist bits where millions were sent to the Gulag or killed due to forced collective farming. Or at least try to present it in the context of doing what they thought best to create a common culture between all members of the former Soviet Union. ? Somewhere you have to present that perhaps, communism wasn't the best form of government. For China, where millions upon millions died during Mao's reign, communism is mostly ignored. That's probably for the best. For Egypt, you'd want to concentrate on ancient Egypt with it's pyramids, sphinx, and life along the Nile, and ignore everything to do with Islam. For India, you'd probably want to ignore the entire history of the Raj and the general animosity with Pakistan.
It's got to be incredibly difficult for Disney to present each country in any way that accurately reflects the history of that country. All should be romanticized in some regard. And as tourists (and probably mostly Americans), can we visit an Egyptian pavilion and not remember the images we've all seen on TV of thousands of Egyptians shouting "Death to America!"?
All in all, I'm beginning to think Brazil would present the least of these problems. It's the best choice.
Future World can never be "fixed". Or perhaps I should say the only fix for Future World is to rename it.