With a PDF file that has a sensitivity label (opened in Revue), is the Microsoft sensitivity label visible in Bluebeam Revue?
If you are securing your files with Microsoft Information Protection as of Revu 21.3 you can now open those files in Revu. If you go to Document → Document Properties there will be an MIP tab where you can see the sensitivity label.
Use Microsoft Information Protection (MIP) with Bluebeam Revu | Bluebeam Technical Support