Correct. We shouldn't call things money laundering that are not money laundering. Mixing is not money laundering.
Bitcoin mixing does fit the state’s definition of money laundering. The point is that money laundering itself does not have a victim.
The state can make anything a crime. But some things are immoral and others aren't. If they aren't then they aren't wrong, no matter what the state says. It's just a question of whether we can do anything about it.
The term "money laundering" is itself a relatively recent term (e.g. no money laundering mentioned in 18th century literature). Like "obstruction of justice," money laundering victimizes the state law enforcement apparatus. It's an invention of a self-preserving bureaucracy. That the state can be "victim" of a crime is itself an absurdity. The mark of an overgrown institution more so than a true matter of morality.