That sounds odd. Just to test, I created a new user and assigned them the VSC Provision role. I was able to create an NFS datastore with no issues.
Here is what my role looks like:
PS C:\Users\bingen> Get-VIPrivilege -Role "VSC Provision" | Select-Object Name
Name
----
Anonymous
View
Read
Manage custom attributes
Log event
Cancel task
Licenses
Settings
Rename datastore
Move datastore
Browse datastore
Remove file
Low level file operations
Allocate space
Storage partition configuration
Security profile and firewall
Advanced settings
Remove
Unregister
Power off
Customize guest
Read customization specifications
Allow disk access
Allow read-only disk access
Create task
Update task
Validate session
Configure a datastore cluster
Manage datastores
Provision
View
View
Update VM storage policies
View VM storage policies
Configure service
View