If I believe that "it is good to reduce net human suffering so others can live fulfilling lives" I'm not sure what evidence there is to give to refute. Some beliefs are "it should" rather than "it is" and in those cases it feels like they fail the crony belief sniff test just as a category.
The answer is that this is not a factual statement about reality. It's a statement about ethics - is this ethical according to your ethical system and beliefs? Ethical beliefs are subjective and always boil down to "I feel this is good".
So this is really a question about what emotions you feel.
I'm struggling to find the purpose of the article, it seems like beliefs of any nature can occupy the title "crony"?
An ethical framework does the epistemological work of observing what humans are and how they feel and behave in various situations and forming generalizations that hopefully aren't too wrong.
This is why arguing ethics across ethical frameworks is so frustrating; the semantics aren't compatible enough.
I think that if an argument is clear, one can always think of counter-evidence or construct at least a hypothetical experiment which can test it.
Ultimately though, my (probably controversial) answer to increasingly abstract ethical questions would be that when the goal is to find what is True then reducing suffering (human or other) as well as other ethical endeavors becomes a necessary by-product.
I saw people in distress -> I thought "that doesn't look fun, I could try to minimize that" -> belief formed.
I struggle to find a devil's advocate position for this let alone any utility in doing so.
This belief makes you very approachable, more than if you didn't believe it.
I guess to undo that belief you'd have to move to an environment where that wasn't rewarded.