It's no wonder that they removed the reference to the zombie plague being started in China in the film World War Z as to not offend the Chinese audience even though that is how it happens in the book.
Exactly! That's the reason they removed that reference.
I would not be surprised to see a Pacific Rim sequel if the film makes $350-400 million worldwide. Because then it would be an established franchise with name recognition and a foothold domestically and overseas. Plus I think the big mistake that was made here was not advertising more to children and a larger toy line production. Graphic novels and such seem to be flying off the shelves. There's a lot of secondary marketting potential for a film like this (and sequels).
Movie studios far prefer to invest in known entities (prequels, sequels, books with large established fanbases, remakes, etc) than betting on original ideas. For example . . . who the hell did the Percy Jackson film rate a sequel? It lost money overall (at least $7 million as reported) and didn't fell short of a $90 million box office domestically.
I wouldn't be surprised if they tried to trim the budget for a Pacific Rim sequel some though just in case.