init does look for it under /etc/
Code:
$ strings /sbin/init | grep initscript
/etc/initscript
OP. is correct, there's definitely an inconsistency here. Whether the sample should be moved to /etc, or sysvinit patched to look for it in /sbin/ I guess is a matter of preference.
Maybe just putting it in /usr/doc/sysvinit* (it is a sample after all) and leaving those who want to install it to do so manually is the right approach.