That was a mistranslation by XIVcore. Read their news thread starting from here:
http://www.ffxivcore.com/topic/17035...16#entry315716 , and look at the quotes below. The post says there WILL be open world NMs, the quotes below quoting the person says there WONT be open world NMs. It was edited to be fixed, which is why the quotes are still wrong and show the mistranslation.
Guy saying he mistranslated:
http://www.ffxivcore.com/topic/17035...34#entry315734
People gotta stop repeating the same wrong information once its been corrected.