*   Clients using older endpoints will be unaffected. This change is only at the REST API level and is independent of the default behavior of particular clients (e.g. this does not affect the default for the kubectl `--cascade` flag).
    *   If you upgrade your client-go libs and use the `AppsV1()` interface, please note that the default garbage collection behavior is changed.

### **Auth**

#### **Audit**

* The alpha `Initializers` admission plugin is no longer enabled by default. This matches the off-by-default behavior of the alpha API which drives initializer behavior. ([#66039](https://github.com/kubernetes/kubernetes/pull/66039), [@liggitt](https://github.com/liggitt))
* kubeadm: Default component configs are printable via kubeadm config print-default ([#66074](https://github.com/kubernetes/kubernetes/pull/66074), [@rosti](https://github.com/rosti))

#### Defaults

 - The default spec.updateStrategy for the StatefulSet and DaemonSet kinds is
 RollingUpdate for the apps/v1beta2 group version. You can explicitly set
 the OnDelete strategy, and no strategy auto-conversion is applied to
 replace default values.

 - As mentioned in [Behavioral Changes](#behavioral-changes), selector
 defaults are disabled.

  - The command `kubeadm config print-defaults` is deprecated in favor of `kubeadm config print init-defaults` and `kubeadm config print join-defaults` ([#69617](https://github.com/kubernetes/kubernetes/pull/69617), [@rosti](https://github.com/rosti))

* Pod priority and preemption is now enabled by default. Even if you don't plan to use this feature, you might need to take some action immediately after upgrading. In multi-tenant clusters where not all users are trusted, you are advised to create appropriate quotas for two default priority classes, system-cluster-critical and system-node-critical, which are added to clusters by default. `ResourceQuota` should be created to limit users from creating Pods at these priorities...

([#58171](https://github.com/kubernetes/kubernetes/pull/58171), [@verult](https://github.com/verult))

* Default values differ between the Kubelet's componentconfig (config file) API and the Kubelet's command line. Be sure to review the default values when migrating to using a config file. For example, the authz mode is set to "AlwaysAllow" if you rely on the command line, but defaults to the more secure "Webhook" mode if you load config from a file. ([#59666](https://github.com/kubernetes/ku...

- Feature gates CSIMigration to Beta (on by default) and CSIMigrationGCE to Beta (off by default since it requires installation of the GCE PD CSI Driver) ([#85231](https://github.com/kubernete...

- Graduated seccomp profile defaulting to GA.
  
  Set the kubelet `--seccomp-default` flag or `seccompDefault` kubelet configuration field to `true` to make pods on that node default to using the `RuntimeDefault` seccomp profile.
  

### Default Container Annotation

Pod with multiple containers can use `kubectl.kubernetes.io/default-container` annotation to have a container preselected for kubectl commands. More can be read in [KEP-2227](https://github.com/kubernetes/enhancements/blob/master/keps/sig-cli/2227-kubectl-default-container/README.md).

### Immutable Secrets and ConfigMaps

- Kube-apiserver: fixes a 1.27+ regression in watch stability by serving watch requests without a resourceVersion from the watch cache by default, as in <1.27 (disabling the change in #115096 by default). This mitigates the impact of an etcd watch bug (https://github.com/etcd-io/etcd/pull/17555). If the 1.27 change in #115096 to serve these requests from underlying storage is still desired despite the impact on watch...