That would be a bit too strong a wording. I would just say that certain theoretical microstates (ones that assume that position and velocity and so on are real properties that particles possess and can be specified by infinitely precise numbers) are not in fact physically distinguishable. Physical microstates do exist, but they are subject to the Heisenberg limit, and possibly other, less well defined/determined precision limits.

Beyond some level of precision, the world becomes fundamentally non-deterministic again, just like it appears in the macro state description.