https://wccftech.com/asus-amd-a520-motherboards-leak/

Not everyone can go out and buy the Asus ROG Crosshair VIII Formula because it is not the most economic option with the extreme premium attached to it. It may have loads of features, but no everyone needs 10GB LAN connectivity and the most powerful VRM on their motherboard. Some people just need some features to operate effectively and the motherboard line that slots in there is the B550 with a decent amount of features for the mid-tier.

A lot of people thought we wouldn't be seeing the A520 series, but Asus' recent listings tell us otherwise. The A520 is the bare bones platform for the AM4 socket. They have all the functionality of all these motherboards with none of the added features.