What's the difference between updatedb.conf and updatedb.findutils.cron.local?

We have some servers that connect to a GlusterFS cluster. According to updatedb.conf these files should not be indexed by the clients, but the cron in /etc/cron.daily/locate doesn't read that file, it reads updatedb.findutils.cron.local instead. The findutils file is empty, so it uses the defaults from the cron which doesn't exclude fuse.glusterfs.

What's the difference between those two files? Should I consider this a bug or have I missed something?