Bulk Tagging and Retroactive Workflow

It would be a nice feature to have a better tagging system.
I love the workflow idea setup in the Admin center, however, doesn’t seem to retroactively apply the rules.

I use the cloud as a UI interface with my archive system attached as a local share, It has over 1,000,000 files and folders dating back almost 15 years. I don’t have the time, nor patience to sit and label each and every one by one.

If there were a way to expand the Workflow tagging to apply to what is already uploaded and attached via external storage, that’d be pretty sick. Also add rules to attach date or file-type tags automatically based on file-metadata and extension.