The cc'd users might have been enabled to receive notifications from the Manage Members screen. Please ask the primary user(s) of the organization(s) to disable the notifications for the cc'd users from the Manage Members screen by following the topic "12.1.5 Selecting Users to receive all Notifications sent to all users within an organization" under the below URL.
Managing Members Within Your Organization: https://communityforce.zendesk.com/hc/en-us/articles/360003044651-12-Managing-Members-Within-Your-Organization