There is an enhancement request to support SDC - "ENH-000117007 - Provide the ability to read *.sdc files within ArcGIS Pro. These Smart Data Compression file types are provided by Esri and should be supported in ArcGIS Pro."
The current workaround is to convert the *.sdc files to a geodatabase.
That enhancement request is closed with this explanation:
The SDC format is no longer supported following the ArcGIS 10.2 series of releases. See the "Deprecation Plan for ArcGIS 10.3 and ArcGIS 10.2.x": http://downloads2.esri.com/support/TechArticles/W32809_DEPRECATION_PLAN_FOR_ARCGIS_10_3_and_10_2_x__...
That would indicate the workaround is the path forward.
Per your own document quote below and you can still read SDC in ArcMap 10.6. The question is will ArcPro ever be able to read SDC files? I am guessing the answer is no?
"[Added November 22, 2013] Esri will continue to support the Smart Data Compression (SDC) format through the 10.2 series of releases (ArcGIS 10.2, 10.2.1, and 10.2.2)."