Mostly irrelevant ("mostly" because if the Holy See is going to provide IPv6 connectivity interconnecting their missions to those states, an ISP delegation might make sense).
The question is how many _interior networks_, not people or states, is the Internet Service Provider operated by the Holy See going to interconnect?
I would have thought that an independent state should have the right to receive at least one PI prefix allocation. The thought of one's country being entirely dependent on receiving its entire space from a (most likely) commercial organisation in another country is not very appealing. Imagine if your country could only get its connectivity from another country, and "diplomatic issues" with that country caused your connection to become unreliable. Whether or not the Vatican can fulfil these requirements, I'd say that every state should have a right to at least one independently routable prefix (both v4 and v6) BB
Rgds, -drc (who has has seen the justification "there are more than 1 billion people" once too often)