Is CFN unaware of something else Pius IX wrote?
"For, it must be held by faith that outside the Apostolic Roman Church, no one can be saved; that this is the only ark of salvation; that he who shall not have entered therein will perish in the flood; but, on the other hand, it is necessary to hold for certain that they who labor in ignorance of the true religion, if this ignorance is invincible, will not be held guilty of this in the eyes of God. Now, in truth, who would arrogate so much to himself as to mark the limits of such an ignorance, because of the nature and variety of peoples, regions, innate dispositions, and of so many other things? "
For the thousand time, the person is not guilty of heresy or infidelity due to the ignorance, but only original and actual sins. This is what this says. The invincible ignorant is not saved on account of original sin, at the very least. This is because only Baptism remits Original Sin. Nobody can be saved without the Catholic Faith.
St. Thomas himself explained that those who die invincibly ignorant, who have heard nothing about the Faith through no fault of their own are still damned for their sins, including original sin, which cannot be taken away without Baptism and the Faith. Original Sin suffices for damnation.