My point is that even completely anonymous data that conforms to what you just said can easily become de-anonymized when contextualized to other "anonymous" data.
> A marketer's definition of anonymized is worthless. It's a fantasy they want everyone else to believe in.
I'm using your definition.
> Does it map to a single, identifiable person or something close enough that the distinction is meaningless?
Also
> If it can be "de-anonymized" then it was never anonymous to begin with.
Well sure, that's the point I was trying to make in my rhetorical question above. Individual pieces of data may be "anonymous" but put together with other anonymous data that can be traced to a single source and suddenly you can figure out quite easily who this person is. The data itself is still technically anonymous but it can be pieced together.