Are you referring to the pins that are on the right-side of the connector block?
Those aren't for a connector- they are jumper headers.
They are used for certain specific configuration features- you place a jumper block which will short between two pins.
In the case of the WD Blue in particular, they are used during certain phases of initial factory configuration. It can also be used to disable the use of spread-spectrum clocking used in the drive's logic to reduce EM emissions.