Levada explicitly noted that this liturgical flexibility reflects a broader emphasis of the Church on cultural diversity in the context of unity in faith: (firstthings.com)
The gifts poed out on the church by the ascended Christ have as their final goal that «we all reach unity in the faith and in the knowledge of the Son of God and become mature, attaining to the whole measure of the fullness of Christ» (vs. 13, NIV). (religion-online.org)
Where are today's counterparts to the giants who gave us the ecumenical building blocks toward unity in faith and order, life and work of the church: Visser t» Hooft, Niles, Nygren, Lilje, Newbigin, John XXIII and others who took Jesus» prayer to heart? (religion-online.org)