The Catholic Encyclopedia 1913 uses the term Living Magisterium in a section title. I do understand your point that the N.O. is manipulating a redefinition of revelation and the magisterium but certainly the teaching authority is living entity. See the CE quote below. http://www.newadvent.org/cathen/15006b.htm
"With regard to the organ of tradition it must be an official organ, a magisterium, or teaching authority."
"Must it be admitted that Christ instituted His Church as the official and authentic organ to transmit and explain in virtue of Divine authority the Revelation made to men?
"The Protestant principle is: The Bible and nothing but the Bible; the Bible, according to them, is the sole theological source; there are no revealed truths save the truths contained in the Bible; according to them the Bible is the sole rule of faith:"
"by it and by it alone should all dogmatic questions be solved; it is the only binding authority. "
"Catholics, on the other hand, hold that there may be, that there is in fact, and that there must of necessity be certain revealed truths apart from those contained in the Bible;"
"they hold furthermore that Jesus Christ has established in fact, and that to adapt the means to the end He should have established, a LIVING organ as much to transmit Scripture and written Revelation as to place revealed truth within reach of everyone always and everywhere."