Interesting idea but a very dumb implementation
The idea that an URL could deliver contact information that then gets updated automatically in other people's databases/phones/Outlook/... is an interesting one.
But the idea that you have to do this on the .tel domain on their terms is a dumb idea.
Instead why not allow any URL to host contact information and just define the XML format that needs to be delivered at that URL. So I can put, say www.linkedin.com/myname/contact on my business card and anyone can plug that into their contact manager to get all of the information I allow them to see.