Hello and welcome to Apple Discussions.
The Canon UFR2 driver is not a happy piece of software when you have the printer connected to the USB port of the Airport. This is due to the Airport USB port not supporting full-bi-directional communications. The UFR2 driver needs to be able to communicate with the printer in order for the installation of the printer queue to work correctly. Since the Airport USB does not permit this, the driver software fails to complete the creation of the network printer queue.
So, if your model only had the USB port, then you would have no option but to move the printer and connect it directly to your Mac via USB. However, because your model also has an Ethernet port, you can bypass the USB port and connect to one of the network ports on the Airport Extreme. This will then allow the UFR2 driver to communicate with the printer and permit the creation of the network printer queue.
If you need help with configuring the network settings on your MF, then please reply.
Pahu