Update observability/observability_enable.adoc

observability/observability_enable.adoc

@@ -581,7 +581,7 @@ spec:
 ----
 <1> Use the `observabilityAddonSpec` parameter to define the global settings for all managed clusters that have the Observability add-on enabled.
 <2> Use the `enableMetrics` parameter to indicate that the Observability add-on is enabled to push metrics to hub cluster server.
-<3> Use the `workers` parameter to increase the number of internal workers in the metric collector process. The internal workers shard `/federate` endpoint requests made to Prometheus on your managed cluster, to the internal workers, and sends separate remote-write requests to Thanos on your hub cluster.  
+<3> *Technology Preview*: Use the `workers` parameter to increase the number of internal workers in the metric collector process. The internal workers shard `/federate` endpoint requests made to Prometheus on your managed cluster, to the internal workers, and sends separate remote-write requests to Thanos on your hub cluster.  
 
 [#disabling-observability-on-a-single-cluster]
 === Disabling Observability on a single cluster