SDk connection string 3 (#1224)

* update comments

* update

src/Microsoft.ApplicationInsights/Extensibility/TelemetryConfiguration.cs

@@ -269,7 +269,7 @@ public IApplicationIdProvider ApplicationIdProvider
         public EndpointContainer EndpointContainer { get; private set; } = new EndpointContainer(new EndpointProvider());
 
         /// <summary>
-        /// Gets or sets the connection string. Setting this value will also set the Instrumentation Key, validate the endpoints, and set the TelemetryChannel.Endpoint.
+        /// Gets or sets the connection string. Setting this value will also set (and overwrite) the <see cref="InstrumentationKey"/>. The endpoints are validated and will be set (and overwritten) for <see cref="InMemoryChannel"/> and ServerTelemetryChannel as well as the <see cref="ApplicationIdProvider"/>.
         /// </summary>
         public string ConnectionString
         {
@@ -300,7 +300,6 @@ public string ConnectionString
                     }
 
                     // UPDATE APPLICATION ID PROVIDER
-                    // NOTE: This can be removed when the Indexer Service goes live sometime in 2020.
                     SetApplicationIdEndpoint(this.ApplicationIdProvider, this.EndpointContainer.FormattedApplicationIdEndpoint);
                 }
                 catch (Exception ex)