updated HPA behavior change

Co-authored-by: Shashank Barsin <shashankbarsin@users.noreply.github.com>

CHANGELOG.md

@@ -20,7 +20,7 @@ Monitor the release status by regions at [AKS-Release-Tracker](https://releases.
   * Calico can now be disabled for an AKS cluster through the update operation. More info [here](https://learn.microsoft.com/en-us/azure/aks/use-network-policies#uninstall-azure-network-policy-manager-or-calico-preview).
 
 * Behavioral Changes:
-  * We now allow customization of istiod and ingress gateway HPA to enable customers to ensure minreplicas does not go too low to break pod disruption budgets.
+  * Customizations to HorizontalPodAutoscaler (HPA) for `istiod` and Istio ingress gateways are now allowed. User can directly edit the HPAs in aks-istio-system and aks-istio-ingress namespaces to customize the HPA. Note that HPA changes that violate minReplicas specified in the existing PDB will be rejected/reset.
 
 * Bug Fixes: 
   * Fixed missing CalicoBlockSize when uninstalling Calico. This fixes a bug that can cause the disablement of Calico Network Policies to fail.