If I am not mistaken, the virtual layer support is available only for VMware, so in the case of VMware, we can monitor the datastore-related activity on your VMware platform.
We have been asking the same for a while as well to help monitor our VMware datastores. I'm sending this chat to our VMware Engineer to contribute with details. We ended up purchasing the VMware Alert extension so that VMware alerts related to Datastore would be caught by DT and raise a problem. It would be better though if DT could just monitor the Datastores directly.