Update docs for copy directory_mode param per #8572

files/copy

@@ -79,8 +79,9 @@ options:
     version_added: "1.2"
   directory_mode:
     description:
-      - When doing a recursive copy set the mode for the directories. If this is not set we will default the system
+      - When doing a recursive copy set the mode for the directories. If this is not set we will use the system
-        defaults.
+        defaults. The mode is only set on directories which are newly created, and will not affect those that
+        already existed.
     required: false
     version_added: "1.5"
 extends_documentation_fragment: files