The Azure SQL Managed Instance option is similar to the Azure Arc-enabled SQL Managed Instance service, but the latter lets organizations continue to use their own infrastructure. The nuances between those two options are described in this Sept. 30, 2020 Microsoft Tech Community post. While the ESU program offers a grace period of sorts for SQL Server 2012 users, its use with on-premises servers comes with licensing requirements. Organizations will need to have Software Assurance coverage, which is an annuity cost. Also, they can only buy ESUs if they have an "Enterprise Agreement, Enterprise Subscription Agreement, a Server & Cloud Enrollment and Enrollment for Education Solutions" licensing, according to Microsoft's end-of-support FAQ document.