Cloud TPU resources in Compute Engine puts it plainly: The Cloud TPU API is no longer under active development. This includes the Google Cloud CLI for the Cloud TPU API and the Cloud Client Libraries for the Cloud TPU API. The Cloud TPU API will receive bug fixes and security updates only. New hardware generations, starting with TPU7x (Ironwood), are supported only through Compute Engine or Google Kubernetes Engine (GKE). No sunset date is published, so nothing breaks on a deadline...