Add caveat when using delete-machine label

Author: Kausheel

docs/book/src/tasks/automated-machine-management/scaling.md

@@ -6,7 +6,7 @@ Machines can be owned by scalable resources i.e. MachineSet and MachineDeploymen
 
 You can scale MachineSets and MachineDeployments in or out by expressing intent via `.spec.replicas` or updating the scale subresource e.g `kubectl scale machinedeployment foo --replicas=5`.
 
-If you need to prioritize which Machines get deleted during scale down, add the `cluster.x-k8s.io/delete-machine` label to the Machine. KCP or a MachineSet will delete labeled control plane or worker Machines first, and this label has top priority over all delete policies.
+If you need to prioritize which Machines get deleted during scale-down, add the `cluster.x-k8s.io/delete-machine` label to the Machine. KCP or a MachineSet will delete labeled control plane or worker Machines first, and this label has top priority over all delete policies. Note: The label only affects MachineSet scale-down; in a MachineDeployment, the choice of MachineSet to scale-down may bypass labeled Machines.
 
 When you delete a Machine directly or by scaling down, the same process takes place in the same order:
 - The Node backed by that Machine will try to be drained indefinitely and will wait for any volume to be detached from the Node unless you specify a `.spec.nodeDrainTimeout`.