- `LabelSelectors` specified in `topologySpreadConstraints` were validated to ensure that pods are scheduled as expected. Existing pods with invalid `LabelSelectors` could be updated, but new pods were required to specify valid `LabelSelectors`. ([#111802](https://github.com/kubernetes/kubernetes/pull/111802), [@maaoBit](https://github.com/maaoBit))

* StatefulSets now include an alpha scaling feature accessible by setting the `spec.podManagementPolicy` field to `Parallel`.  The controller will not wait for pods to be ready before adding the other pods, and will replace deleted pods as needed.  Since parallel scaling creates pods out of order, you cannot depend on predictable membership changes within your set. ([#44899](https://github.com/kubernetes/kubernetes/pull/44899), [@smarterclayton](https://github.com/smarterclayton))...

- Static pods were taking extra time to be restarted after being updated.  Static pods that are waiting to restart were not correctly counted in `kubelet_working_pods`. ([#116995](https://github.com/kubernetes/kubernetes/pull/116995), [@smarterclayton](https://github.com/smarterclayton)) [SIG Node]

- Kube-scheduler now retries scheduling Pods rejected by the PodTopologySpread plugin when related Pods are created, deleted, updated, or when a node matches the specified topologyKey. ([#122195](https://github.com/kubernetes/kubernetes/pull/122195), [@nayihz](https://github.com/nayihz))

- QueueingHint implementation for NodeUnschedulable is reverted because we found potential scenarios where events that make Pods schedulable could be missed. ([#122326](https://github.com/kubernetes/kubernetes/pull/122326), [@sanp...

- The scheduling queue didn't notice any extenders' failures, it could miss some cluster events,
  and it could end up Pods rejected by Extenders stuck in unschedulable pod pool in 5min in the worst-case scenario.