Agreed, this also tosses Gounod, et al, out of the picture.
My larger point is that there is a definite place for Gregorian and other forms of chant and there is a definite place for hymnody, regardless of the Christian source. My own hymnal has hymns from Ephraem Syrus, Bach, Mozart, Haydn, Ralph Vaughn Williams, Charles Wesley, Martin Luther and many many Roman ones. I am happy to see the Roman congregations being encouraged to move from the trivial show tunes now in use back toward reverent hymans. I am not so happy to see the Roman Church use this as one more way to exclude anything not explicitly produced by a Roman. It’s just not charitable and it really does rule out some of the most beautiful and reverent music ever composed.
Secondly, after decades in being in church choirs - some really good, some not - the protestant stuff, for the most part, but not all, really doesn't fit and a lot of times the lyrics are theologically wrong. Nothing against the music, it's just a reality.
The point in this thread is that there are parts of the Mass that have been suppressed in the last 50 or so years - the Introit, the Offertorio and the Communio - that the General Instructions now state MUST be put back in and the preferred musical conduit is chant. These are not hymns. They are antiphons with psalm verses. Hymns are to take a back seat. The article says nothing about the recessional, so I suppose hymns can be sung there, but the antiphons are not to be replaced.
My current choir has a director that has a HUGE collection of music and we actually did gorgeous settings of the Offertory Antiphons during Lent. There's also several standard chant settings for all of it.
It'll be interesting to see how this all shakes out.
Ialways thought Gounod was the Catholic Ave Maria and that Schubert was the one to be avoided.