We found an updated (August 2020) Licensing Guide.
There aren’t major changes from the previous release, with just the version being removed from Azure DevOps Server so that the information applies to all versions, including the recently released Azure DevOps Server 2020.
Find this guide here: https://bit.ly/2G40ep0.
Microsoft release Azure DevOps Server 2020 to the web. The October 2020 Product Terms is already updated for this product and there are no changes to the existing Server/CAL licensing model.
Find the announcement of availability here: https://bit.ly/2J2e1xr.
Microsoft announce the General Availability of Azure DevOps Server; this is the latest version of the product you may know better by its previous name of Visual Studio Team Foundation Server.
There are no changes to the licensing of this new version and you can buy Server and CAL licences through a Volume Licensing agreement.
Alternatively, Visual Studio standard subscriptions include rights to the Server licence and one User CAL, and all users licensed for Azure DevOps Services have CAL rights too.
You can find the announcement here: http://bit.ly/2FgTv7U, along with confirmation that Azure SQL Database can now be used with Azure DevOps Server in an Azure virtual machine.