This has been around for a while on Dell and Lenovo (and probably HPE) systems. I guess it's more flexible than the old-school LPC/ISA device method (can route stuff into a management VM, etc.) and it's super cheap to implement in the BMC because it's just a Linux virtual-ethernet-over-USB thing. Also, some newer platforms probably do away with the exposed LPC bus, not to mention the non-x86 world.