Hi anonymous user,
As far as I know there's no General Availability (GA) date announced yet, some of the Cognitive Services were put into preview just a few days ago:
https://azure.microsoft.com/en-us/updates/new-azure-cognitive-services-and-capabilities-in-preview/
You'll find the Azure services' roadmap over here:
https://azure.microsoft.com/en-us/updates
(If the reply was helpful please don't forget to upvote or accept as answer, thank you)
Best regards,
Leon