Windows Docker images need to build on exactly the same kernel version as the host.
This means that, if we update the host, we need to update https://github.com/jenkinsci/docker/blob/master/8/windows/windowsservercore-1809/openj9/Dockerfile#L2 (and all other assorted builds) - this needs to be done at the same time that the new base images are deployed.
We could tag the VMs with `1909`/`1809` and support both builds for a period of time? But we’re going to end up version chasing every few months.
An alternative would be to use LTSC VMs (and install patches)
The AdoptOpenJDK does not yet currently support 2019ltsc or 1909 images. There is a PR to add them (https://github.com/AdoptOpenJDK/openjdk-docker/pull/365) but that has been sat for a while.