I don’t believe that’s true. Certainly, Latin is the official language of the Catholic Church, certainly, it’s important in our scholarship and in our history. But “Latin truly says Catholic?” No, I don’t think so. There are other Churches that are Catholic outside the Latin Rite. And the Church’s primary function is the salvation of souls…not the preservation of Latin. Can souls be saved by a greater or more expanded use of Latin? I very seriously doubt it.
The Church was saving souls prior to Vat II.
unavoce.org/veterumsapientia.htm
Veterum Sapientia
An Apostolic Constitution of His Holiness John XXIII,
Preservation of Latin by the Holy See
The nature of Latin
…
Nor must we overlook the characteristic nobility of Latins for mal structure. Its “concise, varied and harmonious style, full of majesty and dignity” makes for singular clarity and impressiveness of expression.
For these reasons the Apostolic See has always been at pains to preserve Latin, deeming it worthy of being used in the exercise of her teaching authority “as the splendid vesture of her heavenly doctrine and sacred laws.”…
Thus the “knowledge and use of this language,” so intimately bound up with the Churchs life, “is important not so much on cul tural or literary grounds, as for religious reasons.” 6 These are the words of Our Predecessor Pius XI, who conducted a scientific inquiry into this whole subject, and indi cated three qualities of the Latin language which harmonize to a remarkable degree with the Churchs nature. “For the Church, precisely because it embraces all nations and is destined to endure to the end of time . . of its very nature requires a language which is universal, immutable, and non vernacular.” …
Non-vernacular
Finally, the Catholic Church has a dignity far surpassing that of every merely human society, for it was founded by Christ the Lord. It is altogether fitting, therefore, that the language it uses should be noble, majestic, and non-vernacular.
In addition, the Latin language "can be called truly catholic."0 It has been consecrated through constant use by the Apostolic See, the mother and teacher of all Churches, and must be esteemed “a treasure . . . of incomparable worth.” (11). It is a general passport to the proper understanding of the Christian writers of antiquity and the documents of the Churchs teaching.2 It is also a most effective bond, binding the Church of today with that of the past and of the future in wonderful continuity…