It’s a new, generalizable material-science property at STP. Those almost always find practical uses.

(Off the top of my head, a material that dissipates tension below a certain rate but fails when it is applied faster than that rate seems to resemble a mechanical breaker. As in not an electrical breaker that works mechanically. But one that decouples when you pull on it super hard. Being able to do that in fluids means one can potentially do that at very tiny scales.

More broadly, if simple fluids have a quasi-elastic mode, that has fundamental implications for hydrodynamics. I'd be super curious to know, for example, if anything similar to this occurs in air or water.)