The Gemara (Avodah Zarah 36a) says that a Beis Din does not have the power to overrule a Takkanah of a previous Beit Din. It is generally understood that earlier Batei Din are superior to later ones (due mainly to yeridat hadorot).
The Moshiach is going to be the greatest individual to have ever been born (other than maybe Moshe). Do we have any direct sources that state clearly that his Beit Din will be superior to all others?