Miracast only works over wi-fi and cannot be used to stream to an ethernet-connected device via a standard wi-fi network. Therefore only wi-fi enabled devices can comunicate with other wi-fi devices if using Miracast. AV receivers tend not to be wi-fi enabled and more often than not rely on direct ethernet connections for their networking needs.
Technically both devices need to be Miracast certified for the technology to work, but if you want to stream music and movies to a non-certified device, there are plans for Miracast adapters that plug into HDMI or USB ports to allow this. This is your best bet if wanting to use Miracast with current AV receivers.