A member no longer on A'gon would say that it was because all wire, including in fuses, is directional due to the extruding process. Hoping you can shed some light on this.
That is the prevailing theory, yes. It is also a predictable and repeatable phenomenon. The only complicating factor, when a cable in an audio system has multiple conductors, if all conductors were not aligned for directionality, so that they are all in the same direction relative to their pull or cast as formed, determining directionality becomes splitting the difference between how many conductors are going in one direction and how many in another which can make differences less dramatic. But when you have a single conductor, or all are aligned, it’s incredibly easy to hear the difference.