> I don't see why the law should care in any way about a company populating NULL records.
It cares if the existence of this record still leaks private data. This is why talking about generic "records" here is pretty wrong - actual data is not interchangeable "records" where you can just slap on a generic cargo cult policy and think you're done.
Different use-cases require different data handling. Although, I do agree, for most CRUD cases it's enough to NULL out rows.