Why can't we change the address Message Bases in an organization workspace?
Workspaces, Message Bases
The Shipping and Billing labels displayed in an organization workspace are modified via Customizable Menus > System Menus > Organization Address Types.
Organization address types allow you to maintain multiple addresses for organizations. The default address types are Billing and Shipping. Through the Customizable Menus table, you can also add additional custom address types.