To address the question as to whether or not CloudSOC supports leveraging CloudSOC+DLP Policies to perform metadata tagging (example: Classified, Confidential, Legal, etc.) to O365 resources (such as Files in OneDrive), an evaluation Proof of Concept was attempted on 06/16/22.
DLP + CloudSOC + O365 (Microsoft Information Protection)
The conclusion of the POC is that the integration response rule for tagging O365 meta data is not yet supported; however, this is on Engineering's 'Roadmap' and no ETA is available at this time.
Below is a screen print of a Policy that successfully triggers; however, the remediation action fails to perform the metadata tagging.
Image below is the current options list for Data-at-Rest Response Rules