• https://docs.microsoft.com/en-us/azure/azure-monitor/agents/agents-overview

Using the VM managed disk as a proxy for the machine this one-liner gets the creation date-time of the disk. This is not a perfect solution, but it will work in many cases.

get-azdisk -ResourceGroupName "rg-test" -DiskName "WVD-NA-P-30_OsDisk_1_d4b7de4e2a3247a285502a58e03e820b" |
 select Name, TimeCreated,@{N="WVD-NA-P-30"; e = {($_.managedby -split "/")[8]} }