it is said that it is possible to wirelessly enable supervision :
Supervision can be enabled using the Apple Configurator or by using 3rd party MDM software that support the Apple Device Enrollment Program (DEP). If you use Apple Configurator alone to manage your devices, then they need to be physically connected to a Mac. However, Mobile Device Management software like Hexnode MDM allows you wirelessly enroll, configure, manage and secure those devices
You can wirelessly turn on supervision by configuring a DEP policy in Hexnode MDM. But first, you need to join the Apple Device Enrollment Program (DEP). Here’s all you need to know about getting into Apple DEP
After joining DEP, log on to your DEP portal and set it up to connect to Hexnode MDM server. Here’s a detailed guide on getting that done.
You can now configure your DEP policy right here in Hexnode MDM to enable supervision. Now, have your iPad erased, and during Activation, the device communicates with your DEP server, gets your configured policy and turns on supervision without you having to hook it up to a Mac. It’s best to have your device enrolled with Hexnode MDM at the time of Activation to start using the advanced features available only on supervised devices.
We have included a video on Supervision for iOS devices.
Supervising your iOS devices unlock the extra features such as the silent installation of apps, blacklisting of applications, force web content filtering or set wallpapers, locking down the device into the kiosk, etc.. Supervision lets you have more control over the device.
iOS devices can be supervised by Apple Configurator or Device Enrollment Program(DEP).
Please use the help link to know more about the Supervision of iOS devices.