While running a Storage Class Conversion for a StatefulSet application was noticed that even MTC updates the PVC references on .spec.volumeClaimTemplates[].metadata.name to use the migrated PVC name, it won't update `spec.volumeClaimTemplates[].spec.storageClassName` causing that in case of scaling up the application, new replicas will be consuming PVC created under the "old" or "not migrated"  StorageClass.