Problem
Microsoft Azure is upgrading platform TLS libraries and support for TLS 1.2 is becoming the standard default. Sitecore xDB Cloud customers running a Sitecore version prior to 9.0 may experience communication errors related to Azure Search. This would impact the availability of the Sitecore "analytics" index and related features across the Sitecore platform.
Identified: On February 26th, Microsoft started rollout of Azure Search with enforce TLS 1.2 in use. Rollout started from US regions. Cloud Ops team is monitoring situation, however, recommended solution for customers is to apply the workaround described in KB article referred above.