CDS Starter Portal was a feature mentioned in the April 2019 release notes and if you happen to have a Dynamics 365 tenant that also has PowerApps environment CDS databases provisioned you might have noticed you can actually preview this now!
On a new portal add-on if you go and configure, or on an existing add-on and manage the Dynamics 365 instance you will notice the Dynamics 365 Instance selector contains both Dynamics 365 and Common Data Service databases.
Once you select a Common Data Service database it will automatically select the Customer as the type and then you will notice a Common Data Service Starter Portal (Preview) option as the portal to be deployed!
Once provisioned you will now have a CDS Starter Portal template available. This is basically the equivalent of the Basic or Custom Portal but within a CDS “naked” database (just Accounts, Contacts, and activities).
Go give it a try, remember it is in preview though! Wonder where will see this go and what people will create 🙂