The second type of data densification is known as domain padding. It is fairly straightforward and, unlike domain completion, is discussed in Tableau documentation. We will proceed with a definition and then consider how domain padding is deployed and when it's useful.
Domain padding: The addition of marks to the view through the Show Missing Values option on range-aware dimensions (that is, date and bin) and Analysis > Table Layout > Show Empty Rows/Columns even when there is no underlying data associated with those marks.