I am curious about other situation. Suppose that IANA allocates the last 2 /8s to the RIR A and one day later IANA receives a request from the RIR B that is running out of IPv4 addresses while the RIR A has (at least) 2 /8s.
I don't think that IANA would ever do this because it would be an incredibly stupid thing to do. Since I have never heard IANA being accused of gross incompetence before, I have to believe that when they receive that request from RIR A, they will ask all the other RIRs about how many addresses they need before allocating anything. In fact, I expect IANA to do this well before the last 2 /8 blocks. Then, after consulting all RIRs, I expect IANA to publish their intentions and ask for comments before allocating any blocks. This is just good business practice and I don't think that the RIRs need to write policies which tell IANA to do this. --Michael Dillon