A translation of the broadcast is here: https://en.wikipedia.org/wiki/Gyokuon-h%C5%8Ds%C5%8D#Full_text
It is hard to understand in English, and very hard to understand in Japanese, because it is in highflow pseudo-ancient court Japanese. Many people hearing it did not understand until the afternoon newspapers were published, translating it into ordinary Japanese. My sense is that this publication is the Emperor's way of sending a disapproving message to Abe government about its plans to change the Constitution. The Emperor can never make an overtly political move or say anything, but he can send a signal. - Jed
