Microsoft has announced the availability of SQL Server 2016 Service Pack 2 as shared in following

https://redmondmag.com/articles/2018/04/25/sql-server-2016-sp2.aspx

https://blogs.technet.microsoft.com/dataplatforminsider/2018/04/24/sql-server-2016-service-pack-2-is-now-available/

Microsoft announced the availability of SQL Server 2016 Service Pack 2 (SP2) on Tuesday.  The SP2 release is currently available through the Microsoft Download Center. The publish date is shown as April 9, so possibly it was available earlier than Tuesday.  The release is packed with performance improvements, as well as diagnostic additions, and it includes all of the latest updates through SQL Server 2016 SP1 Cumulative Update 8. Microsoft had released SP1 back in late 2016.