Amit Khandelwal announces a change:
To make this approach scalable & manageable, we will publish SQL Server container images to MCR based on the distribution’s most recent version, rather than publishing it for all versions of both RHEL and Ubuntu. Here’s an example to help you understand:
SQL Server 2017 supports Ubuntu 18.04 as the most recent distribution; thus, going forward SQL Server 2017 container images based on the Ubuntu 18.04 image will only be published to MCR and we will not publish the SQL Server 2017 container images for Ubuntu 16.04.
This seems fine to me. They focus on image support for the most recent fully-supported version and hopefully make it a bit better. I do wonder if that will change their overall Linux policy around version support, as that could be trickier to sell.