But the thought that occured to me was that complex and seemingly unnecessary features like grammatical gender can serve to reduce noise in oral communications.
Languages that mark grammatical gender in articles, like Dutch or French, sharply reduce the number of words that can follow them given their context, while the amount of information that has to be stored in the lexicon to make this gain in noise reduction is very small. In French with just two genders, it’s just one bit of information per noun.
I suspect that by losing grammatical gender, Haitian Creole has had to create other distinctions to compensate. The thing is, given a reasonable corpus, this hypothesis should be empirically confirmable.
PURGGE People United for the Reduction of Grammatical Gender Everywhere