Anyone know if the inverse if this exists for like a USB DAC? XD

It does seem to be blatant lying, yes. USB is just as capable as SPDIF and anyone who says otherwise either themselves doesn't understand the technologies or has bought into the technobabble of authorities who themselves don't understand the technologies. Don't take my word for it!

Unless my receiver has SPDIF in and not USB. I plan on using this on a RasPi to connect to my receiver.