Comment on January 2017 CU for SharePoint 2013 product family is available for download by Stefan Goßner

Hi Sibylla,
to ensure that the whole fix is applied including changes in the database and copying all the files into the right directories PSConfig is required after installing the fix. But usually you can do this in a second maintenance window (e.g.) a couple of Weeks later.
In July was a breaking Change. SharePoint would not work correct if running PSConfig would have been delayed.
This breaking change affects all CU installations which install a CU from July 2015 CU and later on a System with an older CU than July 2015 CU.
Cheers,
Stefan