Does Rome hold that opinion? The unity is in Christ manifested in his Church with the infallibility given to his Church, and governance is “by the successor of Peter and by the Bishops in communion with him”.
In reality, the Council Fathers simply intended to recognise the presence of ecclesial elements proper to the Church of Christ in the non-Catholic Christian communities. It does not follow that the identification of the Church of Christ with the Catholic Church no longer holds, nor that outside the Catholic Church there is a complete absence of ecclesial elements, a “churchless void”. What it does mean is that if the expression “subsistit in” is considered in its true context, namely in reference to the Church of Christ “constituted and organised in this world as a society… governed by the successor of Peter and by the Bishops in communion with him”, then the change from est to subsistit in takes on no particular theological significance of discontinuity with previously held Catholic doctrine.
Code:
... the change from “est” to “subsistit” does not signify that the Catholic Church has ceased to regard herself as the one true Church of Christ. Rather it simply signifies a greater openness to the ecumenical desire to recognise truly ecclesial characteristics and dimensions in the Christian communities not in full communion with the Catholic Church, on account of the “plura elementa sanctificationis et veritatis” present in them. Consequently, although there is only one Church which “subsists” in one unique historical subject there are true ecclesial realities which exist beyond its visible boundaries.
vatican.va/roman_curia/congregations/cfaith/documents/rc_con_cfaith_doc_20070629_commento-responsa_en.html