It's an essential package designed for exactly this.
It's pretty small, so not a huge cost to putting it back in.
The problem is pervasive enough, and it's unlikely that
users will know how to fix it, that it's worth us solving
it in the base image.
sysv-rc and util-linux are used in the postinst scripts
of some packages, and so those packages won't install
if they aren't available.
sysv-rc contains update-rc.d, so any package that installs
a service would fail to install. Those packages are common
to install in to containers.
util-linux contains the getopt command which some scripts
expect to find.
James Westby