Struthio, just because John Damascus uses the phrase in a general sense to refer to the time of Antichrist, does not mean the Vatican Council used it in the same general sense.
The Church can never be without shepherds and teachers. The Church is essentially an unequal society comprised of those with the authority to teach, govern and sanctify, and those who submit to their authority. If the Church no longer had shepherds and teachers who enjoy the three-fold authority, she would undergo an essential change, and therefore cease to be the Church founded by Christ. IF that were to happen, the gates of hell would have prevailed against the Church. Listen to Popes Pius X and Pius IX:
Pius X, Vehementer Nos. 8, Feb. 11, 1906: “The Scripture teaches us, and the tradition of the Fathers confirms the teaching, that the Church is the mystical body of Christ, ruled by the Pastors and Doctors (I Ephes. iv. II sqq.) - a society of men containing within its own fold chiefs who have full and perfect powers for ruling, teaching and judging (Matt. xxviii. 18-20; xvi. 18, 19; xviii. 17; Tit. ii. 15; 11. Cor. x. 6; xiii. 10. & c.) It follows that the Church is essentially an unequal society, that is, a society comprising two categories of persons, the Pastors and the flock, those who occupy a rank in the different degrees of the hierarchy and the multitude of the faithful. So distinct are these categories that with the pastoral body alone rests the necessary right and authority for promoting the end of the society and directing all its members towards that end. … the plan of the episcopate and the constitution of the Church have always been found to be so framed that the Church rests on the Bishops, and that all its acts are ruled by them.”
Please note, that Pius X refers to the final verses of Matthew, just like the Vatican Council: usque ad consummationem saeculi
Pius IX, Mortalium Animos, January 6, 1928: “Christ founded His Church as a perfect society, of its nature external and perceptible to the senses, which in the future should carry on the work of the salvation of mankind under one head, with a living teaching authority … The Church thus wondrously instituted could not cease to exist with the death of its Founder and of the Apostles, the pioneers of its propagation; for its mission was to lead all men to salvation, without distinction of time or place: “Going therefore, teach ye all nations.” (Matt. 28:19). In the continual carrying out of this task, will any element of strength and efficiency be wanting to the Church, when Christ Himself is perpetually present with it, according to His promise: ‘Behold, I am with you all days, even to the consummation of the world.’ (Matt. 28:20). Hence not only must the Church still exist today and continue always to exist, but it must ever be exactly the same as it was in the days of the Apostles. Otherwise we must say—which God forbid—that Christ has failed in His purpose, or that He erred when He asserted of His Church that the gates of Hell would never prevail against it. (Matt. 16:18). … The one Church of Christ is visible to all, and will remain, according to the will of its Author, exactly the same as He instituted it.”
When the Vatican Council says the Church will possess shepherds and teachers until the consummation of the age, it means until the very end.
Well, you already have found that always
cannot mean forever
here, since the mission of the militant Church will have and end. Pius IX specifies the end by quoting the final words of Matthew even to the consummation of the world
. If the Church wouldn't ininterruptedly carry out her mission usque ad consummationem saeculi
, then the gates of hell would have prevailed against her.
Pius IX does not say the very end
. These words jumped out of your upper storey. Pius IX said usque ad consummationem saeculi
, quoting Mt 28:20 and the Vatican Council.
I know that it's hard to unlearn errors. But you have to do that. These two quotes of yours in no way define what you claim they do. Neither does Pius X nor Pius IX say: "usque ad consummation saeculi" means "to the literal last day".