The following occurs in Joseph Ratzinger: Collected Works Vol 11, Theology of the Liturgy, p.568, quoting a paper given by the then Cardinal which is cited as "Translated by Henry Taylor. From Alcuin Reid OSB, ed., Looking Again at the Question of the Liturgy with Cardinal Ratzinger: Proceedings of the July 2001 Fontgombault Liturgical Conference (Farnborough, Eng.: St Michael's Abbey Press, 2003), 145–53." JRCW is published by Ignatius Press.
For the future, we ought to think—it seems to me—in terms of enriching the Missal of 1962 by introducing some new saints; there are now some important figures among the saints—I am thinking, for example, of Maximilian Kolbe, Edith Stein, the martyrs of Spain, the martyrs of the Ukraine, and so many others—but I am also thinking of that little Bakhita in the Sudan, who came from slavery and came to freedom in her faith in the Lord; there are many really lovely figures whom we all need. Thus, opening up the calendar of the old Missal to new saints, making a well thought-out choice of these, that seems to me something that would be appropriate at present and would not have any destructive effect on the fabric of the liturgy. We might also think about the Prefaces, which also come from the storehouse of wealth in the Church Fathers, for Advent, for example, and then others; why not insert those Prefaces into the old Missal?
Thus, with great sensitivity and by showing a great deal of understanding for people's fears and preoccupations, maintaining contact with their leaders, we should be able to understand that this Missal is also a Missal of the Church and under the authority of the Church, that it is not an object preserved from the past, but a living reality within the Church, very much respected in its particular identity and for its historical stature, but also considered as something that is living and not as a dead thing, a relic of the past. The whole liturgy of the Church is always a living thing, a reality that is found above us and is not subject to our decisions and our arbitrary intentions.
This does not explicitly show that users of the 1962 Missal (or earlier versions; the Cardinal is explicit elsewhere in his rejection of discontinuity) should adopt the 1969 calendar wholesale, as the question assumes. But it does point clearly to his assertion earlier in the article that the 1962 Missal should not simply be abrogated:
What was until 1969 the liturgy of the Church, the most sacred thing for all of us, cannot become after 1969—with an incredible positivism—the most unacceptable thing. If we want to be credible, even with this slogan of modernity, we absolutely must recognize that what was fundamental before 1969 remains fundamental afterward: the realm of the sacral is the same, the liturgy is the same.
While this clearly led to Summorum Pontificum, the Cardinal (as Pope Benedict XVI) did not enact his prior ideas of a limited reform of the associated calendar.