They are deleted after ninety days, silently, with no consequence to the employee and no pressure to review.
Anything nobody acts on is deleted after ninety days, silently, with no consequence to the employee and no reminder that says review these or lose them.
If ignoring contacts triggered pressure, people would approve contacts just to stop the reminders, and approval would stop meaning anything. Silent deletion keeps the choice genuine.
Holding contacts nobody approved creates risk with no business purpose. Deleting them on a fixed schedule keeps the store small. See RelationLens.