I think that all that is going on with Brazil is that it's a miniature replica of the Foxconn plants in China, and as been mentioned numerous times, it's only because it would be MORE expensive to make them in China (however inexpensive) and ship to them to Brazil than to deal with an inflexible supply chain in Brazil and make them there. Even factoring in demand and supply volatility. If things don't go well for the plant, on the world scale, it's only Brazil. All of these were factored into the decision to build them there.

China is responsible for making every iPad in the world outside of Brazil. You can't assume the same amount of risk for that scale. If a component goes bad or if demand skyrockets, you want as many responsive factories around as possible to pick up the slack or to get you new components. Why wouldn't you want to locate your supply chain in China? Only if you have a situation that looks like Brazil--high import tariffs.