File transferred via Airdrop

AirDrop is a peer-to-peer transfer protocol - used to directly transfer material between devices. For AirDrop to work, both devices must be in close proximity and/or using the same WiFi network; unless a third-party is also in close proximity, or able to access the same WiFi network, the file transfer process cannot be monitored.

You should also note that an AirDrop transfer is end-to-end encrypted. While the transfer event itself might be detected, the material transferred by AirDrop cannot be decrypted by anyone other than the source or destination device.

No. They can restrict it to only managed locations to provide security and ensure data is not being dropped out to unmanaged devices.