For over a decade MacAdmins have been successfully using this preference in scripts and later in configuration profiles to disable AirDrop. However the payload is not officially documented by Apple.
Another preference that Apple has not documented is the ability to configure the discoverability settings of AirDrop: Everyone, Contacts Only or No One.
The method to set this preference has been revealed over the years, but a recent discussion in the MacAdmins Slack made me realize it has not been widely shared. Read on for the details.