The Nectar m1 and m2 flavors were superseded by m3, r3 and c3 flavors (see Introducing Nectar's New Flavors) and have been deprecated since in January 2019. Some Nectar nodes have subsequently started the process of removing the flavors entirely.
New m1 and m2 instances can no longer be launched in the Monash or QRIScloud availability zones. (This has been implemented for some time. In the QRIScloud case, it happened with the Stage 5 migration.) If you attempt to launch an m1 or m2 instance in one of these AZs, the launch will fail with a "
No valid host was found" error message.