Taking some time to process the current info being provided by Blizzard and seeing People’s responses to it. I can say for myself currently, I’m modestly happy with this development, which is primarily because this was ultimately as far as I was willing to compromise on the matter in a general sense (see here for proof that also links to more proof). I know for some folks they think the door is 100% closed for High Elves joining the Alliance as a dedicated race (be they happy or sad over this.) However, where one door may have very well closed, I see another door that may have very well opened…
Now in my personal opinion, I see 3 possible paths Blizzard can take right now as things currently stand.
Path #1 - Worst case scenario
Alliance & Horde share High Elves via customization and a pure in-name High Elf race option is off the table 100%. Only thing High Elf related we will get anymore after this point is related to customization through Blood & Void Elves, cosmetics, in-game lore, and etc…Neither Faction gets factual, exclusive claim to the pure Quel’Dorei.
Path #2 - Middle Ground case scenario
Blizzard goes down the Pandaren path. A Neutral, pure High Elf playable race is made, and eventually the Player will be forced to choose to join either the Alliance or Horde. Both Factions share factual claim to the pure Quel’Dorei. The Horde would get a new sub-faction of High Elves in their Player Faction through a story partnership with the Blood Elves and the Silver Covenant will officially join the Alliance with a story partnership with the Void Elves.
Path #3 - Best case scenario
Blizzard is possibly setting the stage for the Alliance & Horde to be forced into a single, merged Player Faction AFTER the Shadowlands Expansion. They plan to make a in-name playable High Elf race. But, it won’t be Neutral like the Pandarens were and that is because the Alliance & Horde as we know them now are gone (again) AFTER the Shadowlands expansion. There would still be sub-factions players can join to justify PvP, but the old Alliance & Horde Faction system would largely be destroyed. Thus current coming customization options in Shadowlands for the Blood Elves & Void Elves are purely a short term customization flavor enhancer for the two player races.
I do see a 4th possible path. But, that path is better reserved for a dedicated topic as it covers a lot more than just playable High Elves.