I would say the article is oversimplified, maybe for convience and simplicity. I would not assume it to be "gospel".

Audio is much more complex than DC. As I mentioned in another string, an experiment was performed on another forum, where it was measureably shown that wire "transfers", "transmits" to other wire/components at 10khz, and even lower.

Using shielded cable in analog might be ok except shielded wire tends to have high capacitance, which is not good. As one knows, no capacitor is perfect, but in some situations, shielded cable is necessary. I think there are some brands that manufacture lower capacitance shielded cables, so I would recommend one search out those if possible.