[tjradcliffe]

This is fairly boring because the "incompleteness" is built in to the Navier-Stokes equation from the off, and we (physicists) have been well-aware of it for over a century.

Solutions to the Navier-Stokes equation are turbulent on all scales, but reality is only turbulent down to the atomic scale. This matters practically in rarefied gas dynamics, but it matters formally--that is, to mathematicians--no matter what.

Also, the Navier-Stokes equation is typically solved with extremely simple boundary conditions, but reality has surface tension and whatnot.

Ergo: the Navier-Stokes equation is an incomplete description of reality. This is not news. There may be some news in the generalized understanding of how to turn the atomic-level Boltzmann equation into an appropriate macroscopic equation, but the incompleteness of the Navier-Stokes equation is just not all that interesting.

This is fairly usual in physics: the mathematical language we use to describe reality is in most cases approximate, and leaves out various (physically insignificant) terms, as well as including (physically impossible) solutions (waves that propagate backward in time, etc).