With Summorum Pontificum, Benedict XVI universally liberalized the celebration of the Mass according to the Missal of St. John XXIII.
In the letter to the bishops accompanying the motu proprio to all bishops in 2007, Benedict XVI established that “in the history of the liturgy there is growth and progress, but no rupture. What earlier generations held as sacred, remains sacred and great for us too, and it cannot be all of a sudden entirely forbidden or even considered harmful.”
He added, “I would like to draw attention to the fact that this Missal [that of 1962] was never juridically abrogated and, consequently, in principle, was always permitted.”
According to CNA’s source at the Congregation for the Divine Worship, the modifications to Summorum Pontificum would restore the need to get consent from the local bishop to celebrate it. The source said that this and other possible changes “have been requested by some local bishops, complaining about the need to better regulate the conditions for celebrating the Mass in the Ancient Rite.”
The sourced said that the most common complaint is that “sometimes, the group of people requesting the Vetus Ordo is tiny, and adding such celebration and keeping the church open for such small amount of people can be troublesome in dioceses with priests’ shortage.”
In 2020, the Congregation for the Doctrine of the Faith sent a nine-point questionnaire about Summorum Pontificum to the presidents of bishops’ conferences worldwide, since the Pope wished to be “informed about the current application” of the motu proprio.