Interesting -- I (incorrectly?) assumed this would need to be approved by several regulatory bodies in order to be legal to sell...
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.
FIDO U2F also has a $10k certification process to allow you to use the FIDO logo. I don't think it's worth pursuing for me.
Unfortunately, the $10k U2F certification is not that unreasonable compared to other similar certifications I have seen... As the fees don't just cover interoperability testing, but also legal fees if the trademark or specification must be defended.