|Amcache on Windows 7|
So, what happened? After a bit of investigation on my machines, it was traced to Windows Update KB2952664, which updates the application inventory and telemetry (Microsoft terminology for the programs that monitor application usage) executables and libraries.
The update first came out in April 2015, but it appears as if it was not widely deployed (automatically) until around October.
Both Amcache.hve and RecentFileCache.bcf are updated now. I verified this information by parsing both these artifacts. Amcache of-course, had a lot more detail about the same files. So, don't forget to look for amcache on your windows 7 examinations.