IPv6 in Azure VNET is currently previewing globally- in ALL Azure Public cloud regions.
Announcement (Service Update): https://azure.microsoft.com/en-us/updates/public-preview-microsoft-adds-full-ipv6-support-for-azure-vnets/
Links to Documentation & Samples
Full documentation including sample scripts is available here: https://aka.ms/IPv6ForAzureVNETdoc
A sample JSON template is posted in the quickstart repository: https://azure.microsoft.com/en-us/resources/templates/ipv6-in-vnet/Simon Massey commented
IPv6 support on services such as cloud services is being requested more and more. The inability to use IPv6 across the board in Azure is startling given the industry push to IPv6 adoption. If I find that re-engineering is required to our solutions because of this, I will also take the opportunity to investigate alternatives, I expect more from you Microsoft.