Thanks for the question, Sharon.
We currently do not have a link listing each hotel category change, but as noted, all changes will be reflected in individual hotel websites and Marriott.com by March 8.
N/A from Cat 7 to 8 should really be "No hotels," as there are no hotels making such a category change. I have now made this edit in the original post, for the sake of clarity.
Thanks again!
-Andrew