Your question contains within it the false assumption that the organizational structure known as the Catholic Church is interested in proselytizing. Since Vatican II it no longer promotes the Conversion of Peoples, instead it celebrates diversity of traditions. In past times, The Syllabus of Pius IX proclaimed the singular exclusive truth of the Catholic religion; however, in modern times Benedict XVI has clarified the new position. In reference to the Vatican II document, Gaudium et Spes , he declares it a
"revision of the Syllabus of Pius IX, a kind of counter syllabus"
Benedict XVI, Principles of Catholic Theology, 1982, p. 381:
Lets review the Rejection of The Great Commission
Addressing possibility #3:
The conversions are unlikely to come from the Protestants, since Benedict XVI considers Protestantism a valid Christian path:
The conclusion is inescapable, then: Protestantism today is something
different from heresy in the traditional sense, a phenomenon whose
true theological place has not yet been determined.”
“Cardinal” Joseph Ratzinger, The Meaning of Christian Brotherhood, pp. 87-88:
The conversions are unlikely to come from the Jews since proselytization of Jews is rejected. Cardinal Kurt Koch, President of the Pontifical Council for Promoting Christian Unity (a position he's held since 2010), said;
"We Christians must not bear witness in relation to the Jews to a path
of salvation which is completely foreign to them, as we do with other
The Roman Catholic reflections describe the growing respect for the Jewish tradition that has unfolded since the Second Vatican Council. A deepening Catholic appreciation of the eternal covenant between God and the Jewish people, together with a recognition of a divinely-given mission to Jews to witness to God's faithful love, lead to the conclusion that campaigns that target Jews for conversion to Christianity are no longer theologically acceptable in the Catholic Church
Addressing possibility #1
Conversions are unlikely to come from the Muslims because Francis recently promoted "The Spiritual Fruits" of the the fast of Ramadan and wished them a wonderful Id al-Fitr
The pope also offered good wishes to Muslims at the beginning of
Ramadan during a visit to the island of Lampedusa in Italy on July 8,
saying in a speech, “I also think with affection of those Muslim
immigrants who this evening begin the fast of Ramadan, which I trust
will bear abundant spiritual fruit. The church is at your side as you
seek a more dignified life for yourselves and your families.”
John Paul II has praised Hinduism and Buddhism in a similar way, which can be reviewed in Crossing the Threshold of Hope and other documents.
Benedict XVI referred to "Secularism" as fruit of the faith. So they are not even interested in converting Atheists.