The Deprecated Features for ArcGIS document is updated for every ArcGIS release.
With each release, the platforms and functionality supported in the ArcGIS platform are assessed and adjusted based on customer needs and technology trends. The purpose of the Deprecated Features for ArcGIS document is to provide as much advanced notice as possible regarding these changes.
The ArcGIS 10.5 update, which also has information for ArcGIS 10.4.x, contains the latest information available.
The Deprecated Features for ArcGIS 10.5 outlines the changes in platforms and functionality of the recent ArcGIS 10.5 release.