Content Type - default values applying to all items even those with different content type

Repro:

• Created a custom site column from managed metadata (ProgDocType), set a default value (Policy).
• Added site column to a custom content type (xyzPolicyPages).
• Added this custom content type (xyzPolicyPages) to library.
• Note: did not add site column to the default content type 
• Create an item based on custom content type (xyzPolicyPages)  - go to details view, column ProgDocType listed, default value "Policy" appears
• Create item based on default content type - go to details view of item, does not show ProgDocType column
• Add site column to view - default value (Policy) displays on all items, regardless of content type.
• Create filtered view where ProgDocType = Policy - all files display re: default value for field = Policy even though that field should not be applied to that item since it isn't using that custom content type. 
• Go to Quick Edit - only way to remove this value from the items that should not have this field applied to them