As I maintain, the sole difference between a Blood Elf and a High Elf is political. It was initiated in an ideological schism a mere thirteen years ago in game,
but that ideological issue was rendered moot with the restoration of the Sunwell
. This leaves only the political aspect of their divergence, whether they are Horde or Alliance.
It is not a mistake to conflate looking like a Blood Elf with playing a High Elf. Blood Elves are High Elves. They represent the warcraft ideal of the High Elf trope in fantasy.
An Alliance High Elf would have been born in and lived in Silvermoon for most of their life, so has every Blood Elf.
An Alliance High Elf would have an addiction to magic, so does every Blood Elf.
An Alliance High Elf would be sustained by the Sunwell, so is every Blood Elf.
An Alliance High Elf is a fair skinned, so is every Blood Elf.