A few years ago the Fathers of the Birmingham Oratory (the one founded by Newman) changed their principal Sunday Mass from OF to EF. On the surface, this was not a dramatic change; the OF Mass had been in Latin, ad apsidem, with deacon and subdeacon; the music traditional (chant and polyphony). Communion was received kneeling and in one kind only.
But in fact there was a fundamental difference. In the older rite the celebrant and ministers are servants of the liturgy, as indeed they are in the East. They don't control it. In the new rite, even when it closely resembles the old (especially when it closely resembles the old), those who celebrate it have in effect assembled it from the multifarious options available. They are more the masters of the liturgy than its servants.
It represents a novel and completely different way of looking at liturgy, which is difficult not to see as a rupture.