I really don't like that phrase. It should be "reality has a progressive bias". Progressive is the opposite of conservative. "Liberal" is a specific ideology, and will end up in a position somewhere on the progressive-conservative spectrum based on how progressive or conservative it is.

Specifically it is the ideology of Capitalism, representative democracy, the rule of law, etc... basically the ideology of the enlightenment.

This misuse of Liberal is easy to track the etymology. The colloquial usage of "liberal" does sound like an opposite of conservative, it's basically a synonym for "lenient". But colloquial usage is often totally incorrect in certain contexts, like this one.

People who use "liberal" as an opposite of conservative are just bad at type theory.