That 'unavailable' breed is in fact available, which is the problem with the high elf request. Blood Elves are high elves and are in possession of everything that defines a high elf. The reason they are not accepted as the de facto high elves is not because of anything lacking on their part, but because they happen to be on the 'wrong' faction.
And I have never heard of high elf being an insult for a Blood Elf. That is definitely a new suggestion.