title: Is it mandatory to upgrade CRDs deprecated apiVersions?
body: <p>I have a few external CRDs with old <code>apiVersion</code> applied in the cluster, and operators based on those CRDs deployed.</p>
  <p>As said in <a href="https://kubernetes.io/blog/2021/07/14/upcoming-changes-in-kubernetes-1-22/" rel="nofollow noreferrer">official docs</a> about Kubernetes API and Feature Removals in 1.22.</p>
  <blockquote>
  <p>You can use the v1 API to retrieve or update existing objects, even if they were created using an older API version. If you defined any custom resources in your cluster, those are still served after you upgrade.</p>
  </blockquote>
  <p>Based on the quote, does it mean I could leave those <code>apiextensions.k8s.io/v1beta1</code> CRDs in the cluster? Will controllers/operators continue to work normally?</p>