Since non-Catholic Christians who are validly baptized are in communion with the Catholic Church, albeit imperfectly - since they are members of the Mystical Body of Christ- would it eventually be possible for the Church to recognize and even canonize non-Catholic saints?
*** Unitatis Redintegratio***
“The children who are born into these Communities and who grow up believing in Christ cannot be accused of the sin involved in the separation, and the Catholic Church embraces upon them as brothers, with respect and affection. For men who believe in Christ and have been truly baptized are in communion with the Catholic Church even though this communion is imperfect. The differences that exist in varying degrees between them and the Catholic Church-whether in doctrine and sometimes in discipline, or concerning the structure of the Church-do indeed create many obstacles, sometimes serious ones, to full ecclesiastical communion. The ecumenical movement is striving to overcome these obstacles. But even in spite of them it remains true that all who have been justified by faith in Baptism are members of Christ’s body,(21) and have a right to be called Christian, and so are correctly accepted as brothers by the children of the Catholic Church.(22)”