Regarding continue using In-tree plugin after k8s-1.21

Hello, can I keep using provisioner: in StorageClass after K8s-1.21. While I noticed that K8s-1.21 is the target version “in-tree plugin” removal. If I don’t change my provisioner from gce-pd to csi-driver, will be there any issue after I update K8s version to 1.21? Can the migration feature of k8s still work to translate to csi-driver?

My current K8s version is 1.20