Well, it's a good theory. Being a manuscript from Mexico, it wouldn't be surprising if it had eluded many researchers, who often have an European-centric background. In Brazil there are also manuscripts in the native's, non-written language (tupi) codified by catholic priests dating back to XVI, but those are better understood because the language was kept alive up to the late XIX. If it weren't that, it would be undecipherable by now, maybe called a hoax too.
