Perhaps I misunderstood, but CFUUIDCreate doesn't create an application-specific UUID, it just creates a new, arbitrary, UUID that isn't tied to anything. You could then use that to build your own app-specific UUID mechanism, but the API won't do it for you.
It's relatively straightforward to use CFUUIDCreate as a building block for an application-specific UUID, but you're correct in stating that the API itself simply returns a new, pseudorandom UUID.