Yet you cite an article referring to a phenomenon in which classical systems behave like quantum systems (i.e., we see quantum "weirdness" in the classical realm), which indicates that if there is a "surprise" it will be that classical physics isn't deterministic either:
"A material particle dynamically coupled to a wave packet
at macroscopic scale has been discovered recently and has been shown to have intriguing
quantum-like properties (14). The particle is a droplet bouncing on the surface of a vibrated liquid bath, and the wave is the surface wave it excites. Together they are self-propelled on the interface and form a symbiotic object. Recent investigations have shown that this walker exhibits a form of wave-particle duality, a unique feature in a classical system. This appears because the localized and discrete droplet has a common dynamics with the continuous and spatially extended wave. Various situations [diffraction and interference (3) and tunneling (4)], where the wave is either bounded or split, have been examined. The surprising result is that for each realization of an experiment of this type the droplet has an unpredictable individual response.
However, a statistical behavior is recovered when the experiment is repeated. The truncation of the wave was thus shown to generate an uncertainty in the droplets motion.
This uncertainty, though unrelated to Planck constant, has an analogy with the statistical behavior observed in the corresponding quantum-mechanical experiments.
Path-memory induced quantization of classical orbits (emphases added)
One co-author of the above
PNAS study, Yves Couder, is quoted in the article you linked to and the phenomenon in question is the one investigated in the study.
For the simplest article on the general phenomenon (studied for years) that I could find within a few minutes, see:
Couder, Y., Boudaoud, A., Protière, S., & Fort, E. (2010).
Walking droplets, a form of wave-particle duality at macroscopic scale?.
Europhysics News, 41(1), 14-18.
For more nuanced treatments and studies see the
PNAS study cited above and e.g.,
Couder, Y., & Fort, E. (2012, May).
Probabilities and trajectories in a classical wave-particle duality. In
Journal of Physics: Conference Series (Vol. 361, No. 1, p. 012001). IOP Publishing.