As this post makes clear, there has been *no* "organic development" of the liturgy for approximately half a millennium. The first upshot (of recognizing this) is the utter necessity of completely abandoning the widespread narrative about freemasons, communists, protestants, and other bunglers at work inside V2. While paranoid conspiracy theories fit the temper of our times (and are so much fun), they ought not to be confused with ardent reality.
On the other hand, it should be acknowledged that the two main revisions of the Roman rite could not have taken place at two more unhappy moments in time than inside the sixteenth century or in the flux of the immediate post-world-war realities. In both circumstances, Rome was responding almost completely to external pressures, rather than any internal requirement or real need. As a consequence, the changes codified are really polemical (or, if you prefer, apologetic), rather than, say, restorative or pastoral in impetus.
Put the two together and this allows one to see that all of the events have a completely different gloss than the ones to which we have become accustomed, viz.: Did Pius V leave untouched the rites of more than two hundred years out of some inspired appreciation for their untouchable and venerable 'antiquity'? Certainly not!
... if Saint Pius V rejected across the board all the local liturgies that had come to light from the fourteenth century on, it was primarily because he knew that the ideas of nascent Protestantism had spread and because he realized that sorting out the customs that could be described as "orthodox" from those that were more dubious -- or even downright heretical -- was too difficult a task to be feasible [Crouan, The History and the Future of the Roman Liturgy, p. 75].
The reality is that the destructors have been at work so long that -- barring an unexpected manuscript find -- there is very little prospect of a successful return to origins. Consider, for instance, this little 'zinger' (recounted with a straight face):
Everything started, one might say, when Leo X (1513-1521) called upon Zaccaria Ferreri -- a "humanist" in his approach -- to revise the Hymnal, that is, the book containing the hymns that must be sung as part of the Divine Office. The final product was an almost brand-new book that preserved only a few verses vaguely reminiscent of the old Roman Hymnal [Ibid., p. 70].
It is now almost universally conceded that the seventeenth century revision of the Latin hymnal was a mistake, and that the despoiling of these ancient hymns cannot possibly be defended or justified. The so-called improvements which were made to the texts were, in fact, no improvement whatsoever.