No, the Catholic Church says that these doctrines are equally infallible with scripture. (The Council of Trent itself infallibly defined the Biblical Canon so the Bible is itself part of those "special" doctrines defined as infallible).
The Church believes all Public Revelation (The Deposit of Faith) is divided into two parts. The Scriptures and Sacred Tradition. Scriptures are the part of Revelation that the apostles and prophets wrote down, the unwritten parts of Revelation that were taught by Christ to the Apostles and handed down orally are called Sacred Tradition. When the pope/Ecumenical Council promulgate an infallible definition, they cannot create/receive new revelations, they can only clarify whether a teaching has always been in or is compatible with the Deposit of Faith or not. Here is what the Council of Trent had to say concerning the scriptures:
The sacred and holy, ecumenical, and general Synod of Trent,lawfully assembled in the Holy Ghost, the same three legates of the Apostolic See presiding therein,keeping this always in view, that, errors being removed, the purity itself of the Gospel be preserved in the Church; which (Gospel), before promised through the prophets in the holy Scriptures, our Lord Jesus Christ, the Son of God, first promulgated with His own mouth, and then commanded to be preached by His Apostles to every creature, as the fountain of all, both saving truth, and moral discipline; and seeing clearly that this truth and discipline are contained in the written books, and the unwritten traditions which, received by the Apostles from the mouth of Christ himself, or from the Apostles themselves, the Holy Ghost dictating, have come down even unto us, transmitted as it were from hand to hand; (the Synod) following the examples of the orthodox Fathers, receives and venerates with an equal affection of piety, and reverence, all the books both of the Old and of the New Testamentseeing that one God is the author of both as also the said traditions, as well those appertaining to faith as to morals, as having been dictated, either by Christ's own word of mouth, or by the Holy Ghost, and preserved in the Catholic Church by a continuous succession.
Thank you for taking the time to answer my questions. Although you say, "the Catholic Church says that these doctrines are equally infallible with scripture", the author of the article quoted seemed to be saying the "infallibly" defined ex-cathedra doctrines were more important than those doctrine spelled out specifically in Holy Scripture.
Additionally, the "church" as a body recognized the books and letters written by the Apostles or God's chosen prophets as they were written and dispersed throughout the Christian communities long before there was any "official" recognition of a New Testament "canon". Their "Stamp of Authority" was the authority of the very Apostles themselves and they were received universally, or nearly so, as the Word of God. These writings bore witness with the Holy Spirit within each believer that they WERE from God and their life-affirming and life-changing character only enhanced that assurance. From http://www.the-highway.com/ntcanon_Warfield.html:
The main reason Trent was convened was to answer the challenges that the Reformers presented. One big part of those challenges was the place of authority given to the Holy Scriptures ABOVE the authority of the Pope and Magesterium. All doctrines of the church should be backed up and proved by Scripture. The "Church" did/does not have authority over God's word. It's the other way around.
You state that, "When the pope/Ecumenical Council promulgate an infallible definition, they cannot create/receive new revelations, they can only clarify whether a teaching has always been in or is compatible with the Deposit of Faith or not.". Yet, the one main doctrine the author of the article cites, there is only one clear-cut instance where a pope has taught infallibly: Pope Pius XIIs 1950 proclamation of Our Ladys assumption", is nowhere found in Holy Scripture, was not taught "orally" by the Apostles - even John who was given the duty of caring for Mary - and was not even proclaimed as "infallible" doctrine until nearly two thousand years after the time of Christ. The claim, that the Pope does not "create or receive" new doctrine, is refuted in this one instance where this newly recognized "gift" was actually used, though, there have been many other doctrines created with such assumed authority. It seems that this "symbolic" term/idea/concept was devised as a sort of "hedge" against future challenges to their authority which is why many non-Catholic Christians reject it.