PowerCLI 11.2 appears to require a portgroup for New-VM:
PS C:\> New-VM -Name testvm -ResourcePool testpool -Datastore testds
New-VM : 4/2/2019 8:19:17 AM New-VM Value cannot be null.
Parameter name: source
At line:1 char:1
+ New-VM -Name testvm -ResourcePool testpool -Datastore testds ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [New-VM], VimException
+ FullyQualifiedErrorId : Core_BaseCmdlet_UnknownError,VMware.VimAutomation.V
iCore.Cmdlets.Commands.NewVM
PS C:\> New-VM -Name testvm -ResourcePool testpool -Datastore testds -Portgroup testpg
Name PowerState Num CPUs MemoryGB
---- ---------- -------- --------
testvm PoweredOff 1 0.250
This was not true in 10.0; haven't tested 11.1. In any case, I believe this is the wrong behavior.