Hi there,
Thank you for getting in touch, we do appreciate your time.
When using the KML layer system, this data will be added to the map as a layer, these layers are drawn within the browser, using the JavaScript API which we make use of, provided by Google Maps.
With that said, to our knowledge these files are not stored by Google Maps, although some of the placement data is sent to them for processing, as this is required in order to accurately place the data within the KML file, for example.
Point 4.4.1 refers to the end-users location and IP address being sent through to the Google Maps API. This data may be stored to improve functionality within Google Maps.
I hope this helps?