Update release_notes/acm_whats_new.adoc

release_notes/acm_whats_new.adoc

@@ -84,7 +84,7 @@ For other Application topics, see link:../applications/app_management_overview.a
 
 * You can now use the _Advanced search_ option from the console by selecting the *Advanced search* drop-down button. Specify your query and receive results that match the exact strings that you enter and range-based search parameters. See link:../console/search_console.adoc#search-customization[Search customization and configurations].
 
-* Use the new `workers` parameter in the `ObservabilityAddOn` custom resource definition to add more worker nodes into the metric collector procress to shard federate requests made to your hub cluster. See link:../observability/observability_enable.adoc#enabling-observability-service[Enabling the observability service].
+* *Technology Preview*: Use the new `workers` parameter in the `ObservabilityAddOn` custom resource definition to add more worker nodes into the metric collector procress to shard federate requests made to your hub cluster. See link:../observability/observability_enable.adoc#enabling-observability-service[Enabling the observability service].
 
 See link:../observability/observe_environments_intro.adoc#observing-environments-intro[Observability service introduction].