There is debate about whether in celebrations of the older Mass the new Lectionary, that is, new readings for the Novus Ordo, could possibly be used in celebrations of the older form of Mass.
Art. 6. In Missis iuxta Missale B. Ioannis XXIII celebratis cum populo, Lectiones proclamari possunt etiam lingua vernacula, utendo editionibus ab Apostolica Sede recognitis.
… (My translation) …
Art. 6. In Masses celebrated with people according to the according to the Missal of B. John XXIII, the Readings can be proclaimed also in the vernacular language, using editions recognized by the Apostolic See.
The article says "editions recognized by the Apostolic See". The Lectionary for the Novus Ordo is not excluded.
Years ago, the Pontifical Commission "Ecclesia Dei" clarified that the new Lectionary, for the Novus Ordo, could be used with the older form of Mass. It could be used.
I have no idea how this would be done. But… there it is.
Personally, I don’t know of any place where that was done. It is hard for me to imagine a group who would want that.
However, I don’t believe that a close reading of Art. 6 bears an interpretatio that only approved editions of Readings for the OLDER Mass and only the older Mass can be used. The Art. 6 surely includes approved editions of the Novus Ordo Lectionary.
In 1991 the Pontifical Commission "Ecclesia Dei" issued guidelines to the bishops of the world. Here is the relevant passage:
5.Following upon the "wide and generous application" of the principles laid down in Quattuor Abhinc Annos and the directives of the fathers of the Second Vatican Council (cf. Sacrosanctum Concilium, nos. 51 and 54), the new lectionary in the vernacular could be used as a way of "providing a richer fare for the faithful at the table of God’s Word" in Masses celebrated according to the 1962 missal. However, we believe that this usage should not be imposed on congregations who decidedly wish to maintain the former liturgical tradition in its integrity according to the provision of the motu proprio Ecclesia Dei. Such an imposition might also be less likely to invite back to full communion with the Church at this time those who have lapsed into schismatic worship.