The WHOLE purpose of a "SHARED CC LIBRARY" is to be able to keep a single and universal source of truth for EVERY element within the library across all uses of the element – on all files.

There is an issue achieving this.

When I add an illustrator file to the CC Shared Library from within Indesign, and I go to edit that element, it:

Opens a new InDesign file, where you can make the change,
save the change, and the change is displayed on the thumbnail of the shared element, and does in fact update the shared element.

HOWEVER....

It does not update the element displayed on the InDesign file you're working on!

If The same illustrator file is added to the shared library FROM Illustrator directly, then when you double click on that element in the shared library from within InDesign, it will open IN Illustrator where you can make your changes, and when you save it, it also AUTOMATICALLY updates every instance where that element is used across ALL shared files.

This doesn't;t make any sense. It should not matter how you add the element to the library, IF the library accepts the element.

There is another glitch that even makes this more confusing.

If I have multiple items on a page in InDesign, and I group them together and drag the group over to the CC Shared library, The Library "accepts" the group.

Then, when you double click the element, it opens a new page in InDesign.

when you go to edit the text in InDesign – Text that was created FROM INDESIGN, and save your change, it updates the Library element BUT does not update any instance where that is used.

Again, this doesn't make any sense and seems to defeat the purpose of storing universal items in the library.