I understand that you wanted to know if there is notification which can be set when the supplier updates the catalog on their end. Yes, you can logon to your Ariba Network buyer account[buyer.ariba.com] and go to Administration tab and click on the Notification link. Here you will find the option of "Send a notification when a supplier publishes, updates, or removes a catalog.", type the email address here for the team you want to send this notification to. After you configure this, the next time supplier updates the catalog, the email address that you have configured will get a notification that the catalog content has been changed.
Hope this helps.