And just entering the address/location queries (whether they succeed or not, and whether the user's own satisfaction is implicit or explicit) gives Apple bulk who-queries-what-from-where data that can be manually reviewed or automated-tested in followup processes.

For example, they know how dense their geo-data is; where does the volume of queries most exceed the existing density of data? Which queries actually result in someone following instructions to their terminus, and then not requerying again for a while?

Also: while Apple doesn't have a toolbar reporting every query and click into Google Maps -- as with the Google-Bing search results dustup of February 2011 -- they could be using their own automated process to trickle queries into Google Maps APIs and highlight major discrepancies with their own answers, for engineer/data-entry attention.