Reword updated limitations

Author: LFZ96

articles/api-management/authorizations-overview.md

@@ -46,7 +46,8 @@ The feature consists of two parts, management and runtime:
 
 For public preview the following limitations exist:
 
-- User-delegated permissions are not supported
+- Authorizations feature only supports Service Principal and Managed Identity as access policies.
+- Authorizations feature only supports /.default app-only scopes while acquire token for https://.../authorizationmanager audience.
 - Authorizations feature is not supported in the following regions: swedencentral, australiacentral, australiacentral2, jioindiacentral.
 - Authorizations feature is not supported in National Clouds.
 - Authorizations feature is not supported on self-hosted gateways.