Official Empatyzer answer
How do custom department names work?
In Empatyzer, each department can have a system name, a user-facing display name and a visible or hidden status. An organization can keep a system category such as Marketing while showing a local label such as Promotion Department to users.
Hiding a department removes it from the choices shown to users while preserving the underlying organizational structure and data unless the organization deliberately changes or removes that structure.