One could easily argue that allowing access to personal belongings (Their Home) means that they have a right to choose who enters their home on an individual basis, but this does not adhere to housing rental laws in the US.
This is specifically why laws were created based on equal housing opportunity, but now the rules are being carelessly bent by lawmakers (because new business generates new local tourism and revenue streams) with potentially disastrous consequences.
As a minority myself, I'd much rather rent from someone who doesn't discriminate, or simply rent a hotel room, or even cancel a trip rather than to show up unexpectedly to a potentially hostile or unwelcoming environment. Changing names to initials is a small-minded attempt at solving a much more serious issue.
People who discriminate but still attempt to use AirBNB as a service should not be continually supported by the service, otherwise the company should hold accountability for their listings.