Who am I kidding? You’re not really going to get ready, but let’s talk about this anyway.
SQL Server 2016 mainstream support ends Tuesday, July 13, 2021.
According to Microsoft’s SQL Server support policy, that means from here on out, Microsoft will only deliver security patches, not functional, performance, or stability patches. You can still call Microsoft for help, but if you find a performance issue and they need to build code for a fix, you’ll only be able to get it on the two mainstream supported versions – only SQL Server 2017 and