The High Elven thing is a bit complicated and may confuse players who don’t have a connection to the RTS history.,
This is what I gather so it may not be perfect.
The High/Blood schism never really existed in the way that players seem to think it does.
In the beginning you have the Highborne, that group of Empire Elves who got elevated to nobility because the reigning Queen decided that mastery of the arcane was the be all and end all to being a proper elf.
They lord it over the newly designated “lowborne” who for some strange reason, eventually got really upset over this.
Their queen Azshara deciding that none of her species was enough of a Magic Man for her sets her sights on Sargeras as a suitable mate offers Azeorth as a wedding present. Touched by this offer, he offers to eradicate those pesky lowborne. The Highborne as a group say “Yay! cool beans!” A small group among them aren’t quite as sanguine about eliminating the peasant classes though (Who will put out the trash?) and break ranks. They eventually become important. The rest join Azshara for complete makeovers and a long skinny dip.
Anyway, shenannigans ensue, the world undergows Rapid Unscheduled Disassembly, and the lowborn form a reclusive nation of their own where the social order is reversed and the peasants are now the top dogs. Following severe disagreements about the use of magic and good fashion, the former Highborne get invited to take a very long field trip to “anywhere but here” in the process, they rename themselves to High Elves, and redo their fashions and motifs to a blue and gold theme, ditching the whole night scene entirely.
Fast forward a few thousand years. Khadgar invites Alleria and her crew of High Elves on a field trip. Having picked up a taste for Human Men, she joins up with a young cheerful Turalyon. None of the above are seen again and her sister Sylvannas dedicates a statue in her memory in Stormwind. Before her disappearance, Alleria’s cohorts decide to settle at garden spot near Shattrah on Draenor, conveniently located next to a Horde outpost, and the graveyard of a shattered Draeneic temple. With no postal service to the East Kingdoms, thoughts of writing home fade away.
Meanwhile, High Elves back home get a surprise visit from Prince Arthas. They are a bit put out by the fact that Arthas not only showed up unannounced but that he brought thousands of friends with him, all of them dressed in appalling taste. Arthas points out that he got an open door invite from his buddy Dar’khan. Remember that name, it becomes important later. The High Elves insist that “plus one’ does not mean “plus tens of thousands”. Things get heated when they point out his questionable choice of armor embellishment and things go rapidly downhill from there.
After Arthas and his crew see themselves out, the few surviving Quel’thelans, inspired by their prince rename themselves Blood Elves in memory who had their party tickets canceled early and what the spilled blood inspired in new fashion statements. But this does not help with the fact that they are in a terminal after party disaster, not to mentiion the fact that they are getting really bad vibes from the surviving Humans of Lordaeron who are pretty annoyed that their blood elf comrades are less than enthuiastic when the blood elves insist on surviving the suicide missions they send them on. Things completely fall out when they find Blood Elves consorting with their water sodden cousins, the rechristened Naga.
However a group of Arthas’ former crew, led by Alleria’s little sister, now all grown up as the Banshee Queen come to their aid and invite them to join THEIR new crew, promising and delivering support and protection from their former best friends. But some among the Blood Elves, who really have issues with Orc fashion sense, and missing the good drinking days with the Ironforge Dwarves, and have really gotten tired of the color red, rechristen themsleves High Elves and are pointedly invited to leave.
They do so, but not without taking a Windrunner for their very own, whose main occupation would be to annoy her Blood Elf counterparts in Dalaran, the Comeback Capital. The rest settle in the various spots in the Highlands, embracing new careers as targets of the resident trolls and the upcoming Horde.
After a few decades of settling this out, a group of blood elves start pouring over Dar’khan’s notes, in particular, his push for a new deep violet aesthetic. Lor’themar points out the essential color clash between red and violet and shouts “To the Void with you! , Or the Alliance!” Taking suggestion to inspire their new name, the Void Elves gate crash the Alliance and are welcomed for their promise to put new life into Stormwind’s incresingly staid party scene.
Hearing of this new rave going down in Silvermoon City, Umbric not really fond of brick architecture wangles an invittion for himself and his best buds, including a surprisingly returned Alleria and a lot less cheeful Turalyon, and that is pretty much more or less where we are today.