Q:

Underlying tables,blobs and queues not copied over to new subscription

Team,
When i migrated the storage account from one subscription to another using a migration tool(mig-az) it did not migrate the underlying tables, queues and blobs storage. Is that an inherent nature of migration?
is there a way  to copy over the tables to the storage account in newer subscription? When doing the copy, would there be any downtime to the resources in the older subscription?  Would the data in the older sub be lost?

A:

Having a brief read of the Github page for Mig-Az, this seems to be a tool that just creates ARM templates from existing resources and allows you to apply them elsewhere. If this is the case, then it's only going to create a storage account, not any of the underlying resources or data, this is the nature of ARM templates. 
If both your subscriptions are under the same Azure AD tenant then you can just move them using the Azure portal, there is an option in the resource group to move resources. See here for instructions.
If the subscriptions are under different tenants then you are going to need to manually move your data.

