Authority
Hyrum's Law, and many other "laws" in software development, are not really laws in the same way as "The Law of Conservation of Energy."
Those sorts of laws are observed truths about a field. Best we can tell they are always true, no matter what.
Hyrum's Law is just an aphorism. Its one specific person's view on the field.
This sounds sketchy, and it is, but the state of the computing field is such that aphorisms and personal anecdotes are often the best information we have.