Latin America is probably the most likely breeding ground, I agree. The next really great player will have to have some exceptional physical and mental characteristics, but will be most likely to hone them in a situation where, from a very young age, he intensively plays "street football" to very high standards, and then is talent-spotted and trained within the club system to professional standards.
In much of the global South outside Latin America, you might have the street football, but you don't have a strong domestic football infrastructure or a good spread of talent spotters. In the developed world, you have decent infrastructure for training youth, but nowhere near the same kind of intensity in recreational football for youngsters.