I think the problem is that High Elf Wizards are already called Mages and Archmages.
You'll notice that after the wood elf lords were named highborns, GW changed the fluff of dark elves and renamed their lords dreadlords in order to avoid the similarity.
Haha, GW is really starting to run out of wizardly synonyms for its spellcasters. We have already used warlock, seer, wizard, sorcerer, shaman, mage, and necromancer.