Hi John, 🙂
You can disable the messaging feature in Dashboard > Settings > BuddyPress. please find the attached screenshot.
In case you would like to hide this feature based on rôle, I think this topic from BuddyPress support might help you: Hide private message button with specific conditions.
As this issue is related with BuddyPress, it’s best if you try to reach the plugin authors. They will be more informed and better suited to help you. To go further, we invite you to post your request on their support forums: buddypress.org/support
We remain available for all support requests related with the use of your theme.
Best,