What on Earth does that have to do with Pope Pius XII??
Pius XII as Pacelli worked on the Code of Canon Law in 1917. That involved a lot of changes.
Then Pius XII permitted Holy Mass to be celebrated in the vernacular during World War II in England, France, and Germany. Since people in Europe got used to hearing the Mass in the vernacular, was it no surprise that this New Mass would be forced on us? Pius XII was no dummy.
Finally, Pius XII established Diocesan Liturgical Commissions throughout the world when he published his encyclical Mystici corporis Christi
on 29 June 1943. If the Mass were not broken, why would Pius XII ask all dioceses to establish these diocesan liturgical commissions? What was the purpose of these commission? These commissions ultimately paved the way for the disastrous Vatican II council and the Novus Ordo.
Yes, I realize that the initial papers for Vatican II were much better than the final drafts. Nevertheless, it was Pius XII who initiated the plans for Vatican II, and it was he who initiated all the changes in the Code of Canon Law of 1917.
I have read the encyclical Mystici corporis Christi several times. First for my college classes, then in a study group, and finally as a review. I was never impressed by it as it seemed so deceptive.