Microsoft announced on its support website that future Windows 7 and Windows Server 2008 updates will require SHA-2 code signing support to be installed starting with July 16, 2019. The SHA-1 algorithm has been impacted by a number of weaknesses that made it less secure over the years. Microsoft also advises customers who use Windows Server Update Services to update their servers with the SHA2 updates for WSUS 3.0 SP2 until June 18 to make sure that they can deliver future SHA2-signed updates to their enterprise environment.
Source: https://www.bleepingcomputer.com/news/microsoft/windows-7-and-server-2008-updates-to-require-sha-2-support-starting-july/