.
Actually, the question of contraception was already part of the Deposit of Faith.
Heck, the word ‘condom’ comes from the preaching of medieval bishops against barrier methods, they were “Contra Dominium” …against God.
You seem to think that the very act of questioning means that the revealed truth is open to change. What If the questioners are in error in presuming that it can be?
In bringing up that example, you are showing ignorance of the history of that commission. Artificial Contraception had already been ruled by the Church, through the Deposit of Faith, to be evil. The question before the commission was originally the examination of if hormonal contraceptives were artificial in nature, as they used a natural, biological process to achieve the end. The commission took it upon itself to expand the question into an area where the Church had already ruled. Pope Paul simply restated what the Church already knew to be true.
It was those who opposed clear Church teaching in that matter that were (and are) questioning Church dogma, not I.
In so far as my understanding of Dei Verbum, the Church has given us great examples.
Take Mariology, for example. We have quite a number of revealed truths about Mary. Her Fiat, her Immaculate Conception. One point of further understanding is her role as Mediatrix of All Graces. That is a term that is in the process of understanding exactly what it means to be such a Mediatrix. But it takes away nothing of what we already know of Mary. She will never cease to the the Mother of God, the Theotokos. Her Conception will always be ( and has always been, Immaculate).
That is pure Dei Verbum. Always add to our understanding, never taking away, ( or contradicting) what we already know.
One related question for you, can the teaching of Dei Verbum change? Or is that the single teaching that cannot change