Well, technically, since this device contains a clock, it should go through FCC Part 15 Verification before being sold. However, the FCC doesn't really have the budget to go after every board produced, you have to REALLY mess up to get on their radar...

Since it is USB based, it should technically go through USB-IF interoperability testing, if he wants to use the USB logo. Though actually it looks like he has a VID/PID allocated from SiLabs for this, which is already way better than a lot of inexpensive USB products.