Where was this map from?
(2072 was a while ago, so the odds are good that the people who worked on the product either are not involved with the line anymore, or may not remember, but a starting point would be to identify the product that we are talking about.)
And purely guessing: whoever worked on it was not that familiar with Brazil, and it was just an oversight. But of such things are great plots born -- you could decide that in your game something awful happened to the city, leading it to be mostly abandoned. Perhaps there was especially bad VITAS that killed off a higher than usual portion of the population, and then a large outbreak of feral ghouls that made it so dangerous that many people (and jobs!) moved away. Or maybe there was a toxic industrial accident. Or for reasons that were never explained, the new lords of Amazonia ordered everyone to move out (to Metropole), leaving it as a ghost city.
