Hello Dolinhas ,
The preview you were seeing was related to azure Update Manager UI in preview and must have gone away. Regarding the other questions:
1. How will I know when the update installed and the server needs a reboot (this be for the scheduled Un/Planned Baselines restart months)? I want to set a Task Schedule task to reboot it during an agreed maintenance windows with my users.
<> Update installation will follow the normal maintenance window set in the configuration. For more details review: Automatic VM Guest Patching for Azure VMs - Azure Virtual Machines | Microsoft Learn
2. When exactly is the update being installed (date/time)? Is there way to alert me?
<> To be alerted when an update has just happened, you may use Azure monitor on top of Azure resource graph (help with how to do this is from Az monitor, ARG):https://learn.microsoft.com/en-us/azure/azure-monitor/alerts/alerts-payload-samples
3. Is it possible to use SCCM to manage hotpatching patches on these new W2K22 Images?
<> SCCM is not a fully supported scenario for now.