Same positive result for the security update here....however, I'm fairly certain that you meant to say that the build for 13.1 did NOT show up after install.
Mine has NO build associated with the Mac OS X 10.13.1 listed under "About This Mac" under the Apple Menu.....
It DID disable the previously enabled root user....and it DID properly test to validate that the previous root bypass issue was resolved....and I was able to re-enable and disable the root user appropriately with both the Terminal and with the Directory Utility.
