Hi Jon,
ArcGIS Notebook Server is supported on Microsoft Windows server 2016/2019 and Ubuntu/RHEL Linux OS. The physical machine requirement is applicable to Windows - for supporting Hyper-V. Please see system requirements for more info:
ArcGIS Notebook Server system requirements—ArcGIS Enterprise system requirements | ArcGIS Enterprise
ArcGIS Notebook Server system requirements—ArcGIS Enterprise system requirements | ArcGIS Enterprise
ArcGIS Enterprise on Microsoft Azure 10.7 supports ArcGIS Notebook Server - please see What's new for ArcGIS Enterprise 10.7 on Microsoft Azure—ArcGIS Enterprise | ArcGIS Enterprise . You need to use an instance type that supports nested virtualization. If you are using cloud builder, it will automatically filter the instance size selector.
Support for installing Notebook Server using AWS cloud formation templates is not available for ArcGIS Enterprise on Amazon Web Services 10.7. However you can use the setup/installer and manually install and configure Notebook server on AWS. Please note, for Windows on AWS, a bare metal instance should be used*.
Thanks
Ravi
* Please see an updated post further down regarding support for Notebook server on AWS.