Actually, no, Nishant (an apostate who professes that Bergoglio has the true faith), Ladislaus (who also doesn’t believe in Catholic teaching and holds that one may consider Bergoglio to have the true faith), etc. are wrong, and MHFM is correct that the term Co-Redemptix is not a title that is consistent with Catholic teaching. If you think you are correct, try defining the term ‘Co-Redemptrix’ in one sentence and specifically explain what it means in reference to the act of Redemption.
First, you contradict Trent’s dogmatic statement that Jesus Christ ALONE (solus) is the Redeemer. Note that this declaration is made in the context of the veneration of the Virgin Mother of God. It thus would have been a precise opportunity to connect the Blessed Mother to the title of ‘Redeemer’ or to the act of Redemption but Trent did not. In fact, it used the opportunity to declare that Jesus alone is the Redeemer.
Pope Pius IV, Council of Trent, Sess. 25, On Invocation, Veneration and Relics of Saints, and on Sacred Images, ex cathedra: “… the saints, who reign with Christ, offer up their prayers to God for men; and that it is good and useful to invoke them suppliantly and, in order to obtain favors from God through His Son JESUS CHRIST OUR LORD, WHO ALONE IS OUR REDEEMER and Savior… And they must also teach that images of Christ, the virgin mother of God and the other saints should be set up and kept… But if anyone should teach or maintain anything contrary to these decrees, let him be anathema.” (Denz. 984)
Second, Florence’s definition is even more to the point in refuting your false teaching on this matter. It solemnly defined that Jesus Christ ALONE (solus) laid low the enemy of the human race, destroyed man’s sins, and opened up the gates of Heaven. You profess that Jesus Christ did it with Mary. That is false. And note here that I’m citing dogmatic statements of the highest authority, not fallible statements.
LATIN: Firmiter credit, profitetur et docet, neminem unquam ex viro feminaque conceptum a diaboli dominatu fuisse liberatum, nisi per fidem mediatoris Dei et hominum Jesu Christi Domini nostri: qui sine peccato conceptus, natus et mortuus, humani generis hostem, peccata nostra delendo, solus sua morte prostravit, et regni caelestis introitum, quem primus homo peccato proprio cuм omni successione perdiderat, reseravit: quem aliquando venturum omnia Veteris Testamenti sacra sacrificia, sacramenta, ceremoniae praesignrunt.
Pope Eugene IV, Council of Florence, “Cantate Domino” 1441, ex cathedra: “The Holy Roman Church firmly believes, professes, and teaches that no one conceived of man and woman was ever freed of the domination of the Devil, except through the merit of the mediator between God and men, our Lord Jesus Christ; He who was conceived without sin, was born and died, ALONE BY HIS OWN DEATH LAID LOW THE ENEMY OF THE HUMAN RACE BY DESTROYING OUR SINS, and opened the entrance to the kingdom of heaven, which the first man by his own sin had lost…” (Denz. 711)
The key portion for this discussion says: “qui… solus sua morte” (i.e. who... alone by His own death) laid low the enemy of the human race, opened Heaven, destroyed man sins, etc. That is what the Catholic Church firmly believes, professes and teaches: that Jesus Christ alone redeemed man. You profess that Jesus Christ did so with Mary. Your position is not consistent with this dogmatic definition, and this is the highest pronouncement of the Church. Everything is to be understood in light of this, not the other way around. Everything must be corrected to match this, not the other way around. Those who don't profess what the Church does on this (that Jesus Christ ALONE did these things) don't profess what the Catholic Church does.
It’s also interesting how heretics like Nishant, when they deal with the post-Vatican II sect, restrict papal infallibility to the most narrow conditions. They limit it essentially to ex cathedra statements. But when they try to find support in a pre-Vatican II statement for their false doctrines and positions, infallibility suddenly becomes very wide and broad. It's another example of dishonesty, demonic inconsistency, and a false position.
(By the way, in case you didn't know, Garrigou-Lagrange is not an authority in the Catholic Church. He was a raging modernist heretic who openly taught that Jєωs, Muslims, etc. can be saved, and that most Protestants and schismatics are saved. He had no faith whatsoever and no fidelity to Catholic truth. It was false teachers like him who paved the way for Vatican II.)
Also, any citations people bring forward on this matter, unless they reference the original Latin with a verifiable source, are not worth much, as there are numerous mistranslations circulated on this topic, and the precise wording and terminology is very important.