When they implemented Goblins, did they just slap the old goblin models into the character creation? No. When they implemented Worgen, did they just slap the old worgen models into the character creation? No.
When they made blood elves, did they just slap the old "high elf" model into character creation and give it green eyes? No.
I assure you that if they were to make the High Elves a playable race for the Alliance, they would most likely reskin or remodel them from scratch.