He also asked Catholics to join him in praying “for the reunification of all Christians.”
Catholics are united. They are united through their public profession of the Catholic Faith. This is a condition of visible membership in the Church and it is the unity required of all Christians. It is a unity that cannot be lost because it is a miraculous characteristic of Christ's Church, a mark that sets the Catholic Church aside from all false bodies. There is no "re-unification." There is only conversion.
Interestingly the Conciliar-Synodal Church lacks any unity of faith, like all false bodies. It openly professes that schismatics and heretics are also part of the Church of Christ and uses
already condemned partial-communion theology. The Concilliar-Synodal Church is of itself not a declared condemned sect, so Catholics are not required to leave it. It obscures the Catholic Church with many Catholics intertwined amongst it.