Well, take for instance my case: i use HFS as a server for large video file. Anytime a new file is added, a light flash video preview is created. Without this event, it would be complex to implement autorenaming of previews (eg. you will need another software, like a folder watchdog).
Remote renaming of a file can be considered an administrative-level action, so another use of this event can be to notify in some way the admin that that kind of action has been performed,and by who.