I must be missing something.
If something is a fluid... or at least a liquid... that means it... flows, right?
Flow speed isn't infinite, so whenever you pull apart a liquid, you'll see some remnant of the pre-flow state. The thicker the liquid, the slower you need to pull it apart to see that.
Is this surprising? Why wouldn't every liquid do this? In what way is this somehow special to some liquids and not others?
Cavitation can be another “out” for that energy.
Your intuition is correct, and what you’re describing is cavitation - which the article goes on to mumble about a little. Honestly, I am also struggling to see what the novel result here is. You can snap off a drip of pitch by pulling on it - if you shear it, it will probably just bend - yank on the droplet and it comes off with a satisfying snap.
But then again I suppose if you lead a cosseted life, never played with the contents of a shed, and had your first practical experience of actual hands on behaviour of viscous liquids in a lab… you might shout “Eureka”.