I’ve never understood why anyone would assume that, Just because the South America (or Arctic, Australia, or now South East Asia) packs are done, that those regions will not be ‘revisited’ but it makes even less sense to me now that the aquatic pack has demonstrated that it is not true... Both South America and Arctic have already been revisited (Giant otter, Dearf Caimen and Grey Seal) and there is zero reason to think we won’t get more animals from these regions (or Australia) in the future.
That is exactly my point, if there were plans to introduced additional South American animals in the future, something that has already happened, and will most likely continue happening, then breaking it down into subcategories would have been more suitable for everyone involved. At the time considering that Frontier is usually quite about future plans, there was a lot of discontent. I remember even reading negative reviews about the dlc because of this, something that as you said was unnecessary.