Pope Paul VI could have abrogated the TLM if he wanted to. A pope has the power to loose the law what another pope bound in promulgating that law: the principle that holds this is that "equals have no power over each other" (par in parem potestatem no habet
). Father Dulac made this clear in a statement:
If a Pope has the power to lose what another pope by the same power has bound, then he should use this right only for the gravest possible reason (my emphasis): reasons which would have prompted his predecessor to revoke his own law. Otherwise, the essence of supreme authority is itself eroded by successive contradictory commands.
If Pope St. Pius V had reason to revoke Quo Primum
for any reason, then Paul VI could and would have reason to do so. Therefore it is for this reason that Quo Primum
will remain a law unto perpetuity.
As for the issue of granting universal right to every priest to celebrate the TLM I would not be surprised that less than 10 percent of the Novus Ordo priests (speaking of those priests inured in the NOM the past 25 to 30 years, and not including the newly ordained five years or less) would bother to take advantage of this right. It would mean retraining in a totally different environment. And who would take charge of taking this task to train these priests who have been comfortable saying the NOM -- out go the adlibs, the wisecracks to elicit laughter and giggles from the congregation, no more adding or taking away some prayers, but to plunge themselves into some very serious business and for what? as they will be celebrating the TLM only once a week as the bishop will "tolerate." I know of two priests who "taught" themselves to say the TLM. Both prayed the Canon aloud, and bungled most of the rubrics. A third priest said the TLM facing the people in a free standing altar, and horrors, even suggested to bring on an altarboy girl. The congregation groaned aloud and voiced an emphatic "NO WAY!"
The priests incardinated in dioceses where the bishop forbids the TLM (which make up at least 80%) will think twice before attempting to take advantage of the universal right. That's a given.
And the "faithful": how many of these will adapt to this "new" rite? There are numerous factors that will turn them away, Latin being the main one. Boredom will be the second factor. They have been used to being entertained and all of sudden the solemn aura permeating in the sactuary will be somewhat shocking. [EDIT TO ADD: flipflops, tanktops, shorts, revealing cleavages, etc. Unthinkable at the TLM, but wait and see, this will still be the norm. The ushers will still let them in] The altar will have to be moved away from the center and relocated to where it used to be. These are just a few reasons that have to be considered if a priest decides he will exercise his right to say the TLM. And then again, the NOM will still be the Rite that will remain and the TLM perhaps once every two Sundays, and nobody will show up, except a few oldtimers and the curious. But it may be a good start and in time, God willing, the TLM will gain more adherents. A good, if not the best, for the restoration to get a new start. In the next 40 years, the NOM will be in the minority, Deo volente. Oremus.