RFC 5514 is an "April Fool's RFC" and meant to be funny. Eric Vyncke took the joke one step further and developed a Facebook application to implement it, thereby being the first every April Fool's day RFC to have a practical implementation.
Now, if you mean "Does a Social Networking Platform have any benefits to use IPv6 as a transport," I would say the benefit is no lesser or greater than any large scale internet based platform.