It is completely unimportant that those monsters are our closest genetic family on this planet, and the quote from an old survivor that “[they would] make sure that [this place] is not for humanity” is merely a throwaway line! We don’t have to worry about that part of the map, it holds no narrative significance! (I have not finished the whole current story yet, feel free to tell me if my assumption is disproven by basic current facts, I don’t believe in spoilers anyway)