The concepts boil down to deterministic and non-deterministic. Tacking on “functionally” and “truly” onto terms like random and chaotic only tells us how each individual views the dividing line between deterministic and non-deterministic. More to the point, it is about classical mechanics v. quantum mechanics.
As others have mentioned, it is possible for quantum effects to have a strong influence on how a system evolves, and in that case it would be non-deterministic. Instead of worrying about how well we can measure stuff, we should instead be focused on how much influence quantum mechanics has on the system. Does that make sense?