** Updated 2021 ** links below for Azure diagrams template (subscription) or Azure diagram templates download.
This is the official set of Azure Visio Stencils listed on the Azure portal to use in architectural diagrams, training slides, your own documentation and videos as appropriate to explain Microsoft products and technologies.
You can drag and drop the SVG files into PowerPoint or Visio and other tools that accept SVG format.

This download contains a set of symbols/icons to visually represent features of and systems that use Microsoft Azure and related cloud and on-premises technologies.
Heres the updated download of the Microsoft Azure and cloud icons for Visio and PowerPoint.
Azure diagrams template (subscription)
https://support.microsoft.com/en-us/office/create-azure-diagrams-in-visio-efbb25e7-c80e-42e1-b1ad-7ef630ff01b7#bkmk_cne
Azure diagram templates for Visio 2019, 2016, and older versions (non-subscription)
https://docs.microsoft.com/en-gb/azure/architecture/icons/
very good information
Thanks Eduardo!