ECC reporting is part of the memory controller (which is unified across all Zen architecture parts), and is fully supported and functional. You can see the reporting working as expected within the Hardware Canucks article linked in the grand parent.
The article you linked mentions that ECC reporting is not working with the on-board IPMI controller (which presumably means that ECC events aren't being logged in the SEL). While that might be a limitation of this board (and other IPMI-equipped AM4 boards), reporting from within the operating system will still work.
The article you linked mentions that ECC reporting is not working with the on-board IPMI controller (which presumably means that ECC events aren't being logged in the SEL). While that might be a limitation of this board (and other IPMI-equipped AM4 boards), reporting from within the operating system will still work.