This is interesting...
Two thoughts:
First: The most perfect fluid (to date)... liquid Helium in cryogenic conditions. (superfluid)
And...the article describes the expectation of finding this primordial fluid to be like a gas, but finding it instead like a liquid. The difference between the two is a fixed volume of a liquid (usually as a function of temperature).
The discovery implies a model of inter-particle bonding of some kind. (We aren't dealing with atoms here).