I'm afraid it's not. And don't abuse the writings of the fathers and Saints. That's more you have to answer for, not to me, but to God.
We, as Catholics, want to believe that when Holy Mother Church proclaims a Saint, that they were Saintly, in fact. We look to the example of the Saints. They're our guides in the one question we have to decide in this life - for God, or against, and if for, what are His rules for us? what then, in other words.
If the Pope wakes up one morning and says, Kofi Annan is now a Catholic Saint, even you might hesitate to call that an exercise of the Extraordinary Magisterium. I, and all Catholic, and those you quoted, have a much lower, and much more reasonable and holy threshold. There are procedures. There are miracles to consider, and so on.
You toss all that, and the Pope wakes up one morning with Kofi on his mind, and you just keep digging yourself deeper, instead of obeying The Church in her time of historic distress.
Talk about a strawman. Of course the Pope saying something to no one while sitting in bed isn't an exercise of the Extraordinary Magisterium.
we teach and define as a divinely revealed dogma that when the Roman Pontiff speaks EX CATHEDRA, that is, when, in the exercise of his office as shepherd and teacher of all Christians, in virtue of his supreme apostolic authority, he defines a doctrine concerning faith or morals to be held by the whole Church, he possesses, by the divine assistance promised to him in blessed Peter, that infallibility which the divine Redeemer willed his Church to enjoy in defining doctrine concerning faith or morals. Therefore, such definitions of the Roman Pontiff are of themselves, and not by the consent of the Church, irreformable.
There is nothing in here about the procedures the Pope has to follow. All definitions in virtue of the supreme apostolic authority concerning faith or morals to be held by the whole Church are infallible - including all solemn definitions of sainthood:
For the honour of the Blessed Trinity, the exaltation of the Catholic faith and the fostering of the Christian life [concerning faith], by the authority of our Lord Jesus Christ, of the holy Apostles Peter and Paul, and our own, [in virtue of his supreme apostolic authority] after due deliberation and frequent prayers for the divine assistance, and having sought the counsel of our Brother Bishops, we declare and define [defines] that Bl. Pio of Pietrelcina, is a saint and we enroll him among the saints, decreeing that he is to be venerated in the whole Church [to be held by the whole Church] as one of the saints. In the name of the Father, and of the Son and of the Holy Spirit.
All the conditions exist. It is IMPOSSIBLE that Padre Pio is not a Saint.