Well, no I mean Humans are getting purple eyes and the lore isn’t exactly, all there, in my book.
Blood Elves getting purple eyes suits all classes, because you could either be a Mage (which makes most sense) or you could have been one of Kael’s Sunfury in Netherstorm. Purple eyes can still work.
Like I said, Humans might be getting a purple eye colour, so why not the Elves? (Both Night Elves and Blood Elves as well.)
Blood Elf Warlocks were a big TBC thing. Since the Sunwell’s restoration, the use of fel magic hasn’t been necessary. Hell, even Sunreaver Magi remembering using fel and dropping it.
Well the Shal’dorei have purple eyes and last I checked, they mainly used the Arcane.
I see no reason as to why a Night Elf or Blood Elf Magister/Magistrix, couldn’t have purple eyes. Night Elves are getting purple tattoos - coupled with purple eyes, I can see a savage elven arcanist on the Alliance and with the Blood Elves, we have a reserved and more elegant elven arcanist.