Question about Kubernetes Auth Method

I have a question about Kubernetes Auth Method regarding the caveats section Kubernetes - Auth Methods - HTTP API | Vault by HashiCorp :
When the Vault runs in k8s pod - Does system:auth-delegator ClusterRole is automatically binded to Vault service account if kubernetes_ca_cert and token_reviewer_jwt are not specified? or should I add such ClusterRoleBinding myself in that case? Thanks