For now. Spanish Central America is pretty firmly established by now but South America could very easily end up Protestant. Hypothetically the Huguenot colony in Brazil could boom as some alt Great Migration see's tens of thousand of French Huguenots flee France resulting in a French Brazil. Britain meanwhile could found a colony on the Rive Plate resulting in a British Argentina while Chile and Bolivia could be conquered in due course and go the way of French Canada.
Obviously, I will neither confirm or deny any such speculation, but I will say this--if you all recall, the multi-volume Wars of Religion history mentioned earlier ended on "The American Wars".