Legends are created based on the System Settings. Also as you may know Legends are static, so just changing to the Sub-Division will not update the existing legend to Sub-divisions. It would need to be deleted or placed on a layer which is turned off / frozen and a new legend created. In the legend form the item text check box always says Cost Center, but it will display which ever hatch style is selected in the system settings. I will let ADSK know that the name should be updated to which ever hatch style is selected. I have attached a screen shot showing a old Cost Center legend and the Hatch / Legend for Sub-Divisions is displayed below / on the floor plan.
Stephen Komisarek
Technical Consultant
AEC-AC