No, they're not usually, but some superstitious people are adequately dimwitted to subscribe to that. I volunteered with rescue animals for years, and overheard some adult European lady with unplace-able accent malign black cats to her daughter, who was of a different mindset.
The others standing around who overheard it were like "what. the. fuck?".
Anyway, that NPR and whoever Josie Fischel (the author) is decided to publish and thereby perpetuate this nonsense, shame on them both.
That they pointed out this was a black cat being heroic: good on them.
Shelters don't need more nondiscerning humans fearful of black cats.
Your own reply references the aversion to black cats that you argue isn’t there.
You could easily start a discussion about cognitive capabilities of cats for example. How did the cat know that this was a situation that their owner could not get out of on their own? Why did the cat know that other humans could be of help? Why did it even care?
Is it likely to happen here? Nah. (Cat scientists, where you at?)