The question presented as an example is way off-topic, and there have been varying explanations and justifications for what's being asked.
While the question currently asks whether the Church ever retracted a statement made ex cathedra, there's a bunch of speculation about what constitutes a statement made ex cathedra and if the Church is justified in making statements ex cathedra under certain conditions.
Additionally, Hendy's answer here points to a completely different question: whether statements made ex cathedra (or even papal infallibility, a whole other topic) are falsifiable in principle.
So we have a bunch of questions:
- Has the church ever retracted a statement made ex cathedra?
- What constitutes a statement made ex cathedra?
- Under what conditions is the Church justified in making statements ex cathedra?
- Is papal infallibility identical to making a statement ex cathedra?
- Is papal infallibility and/or are statements made ex cathedra falsifiable in principle?
This list alone should point to the question being an excellent candidate for closure as not a real question: it's not clear what is actually being asked other than something related to papal infallibility.
But taking each question by itself, all but the first are off-topic here: Skeptics.SE is not in the business of questioning doctrines of faith. They'd all likely be great questions for the up-and-coming Christianity.SE, but they are bad questions for here.
So it just leaves one question, which is what the question title has been edited to be (nevermind that's not the question body asks, or what people answered). This question is wholly uninteresting: it's a yes or no question that's easily available to anyone who looks (spoiler alert: the answer is no). It's not a question of scientific (or any other kind of) skepticism: there is only one authority who is capable of retracting a statement, and you just need to ask.
Think of it this way: let's say I make the statement "Puppies are ugly." You can ask me, "do you retract that statement?" If I say "no," that's it. There's no deeper mystery here, and there's no need for skepticism: I just provided you the answer to the question, "Did Mark Trapp ever retract any statements about puppies being ugly?"
Being a religious institution does not add more mystery to such a question, which is why I can appreciate how the question turned into this amorphous blob of several other interesting (but wildly off-topic) questions. But being uninteresting isn't a justification for keeping a question open or for it to go off the rails like it has.
To the other questions in the catholic-church tag, they all seem to be valid and on-topic questions for Skeptics.SE, although tagging them all as such seems to be misguided:
These questions aren't about the Catholic Church: they're claims made by the Church. In some cases, the claims questioned aren't even exclusively held by the Church. It seems as pointless to tag them catholic-church as tagging a question "Is the sky blue?" with mark-trapp because I told you it was green.