When some data, like .iso, custom folder, etc..., and VMs are created in WorkloadDatastore, they take VMC Workload Storage Policy - Cluster-1 as their storage policy by default.
VM's storage policy would be changed by vSphere Client > VM > Configure > Policies.
However, the storage policy of any data except VMs would not be changed by above steps.
You also cannot check the current storage policy contents which is applied to the data if the contents of original default storage policy is changed after creating the data.
If you need to change the storage policy that is applied to some data, please remove the data and re-create them in WorkloadDatastore with new storage policy or please contact to VMware Support for further assistance.