High Elves and Blood Elves share a shape and a form, so there is that.
As for 'way' the Blood Elves control the high elf lands of Quel'thalas, they control the high elf capital of Silvermoon, they control the high elf government, they control high elf organisations such as the Magisters and the Farstriders AND they are highly suspicious of and distrustful of Humans, just as good King Anasterian was.
So everything you said there is provably wrong.
Saying their story, theme and goals have diverged implies and equality of different paths, which is not the case. The exiles theme has in fact disintegrated as they assimilate into their host societies. Their story was always as foils to the Blood Elf storyline, used an Alliance counterpart, a role now usurped by the far more appropriate Void Elves.
Ion understands the lore just fine, let me assure you, it is the pro High Elf community that has issues with the lore as is and wishes to retcon or overhaul it to facilitate their goal. After all, for all the gushing and praise Traycor received at the start of this thread with his concept art and attempts to create a unique visual for the High Elves, not one pro High Elfer called him out for the fact that what he was proposing had no basis in lore nor in the known history of the High Elf race. It's implementation in game would have been a colossal rewriting of established lore, yet that implicit issue was never actually engaged with by those who applauded his efforts.
It is hypocritical to suggest the devs don't know the lore when the suggestions supported by the pro High Elf commentators fly completely in the face of established canon and are supported because they are in service of their overall goal. Ion telling you to go Horde was the truth, and the snarkiness of his tone should put paid to this idea that Blizzard won't take a certain course of action (such as blue eyes for Blood Elves) because it offends your sensibilities. If you seek a traditional high elf, that is where you will find one. Just as if I wish to play the closest thing WoW has to a wood elf, I must go Alliance. Faction matters.
Because faction matters, not everyone can be happy as Pennem wisely stated a few weeks ago. Sometimes your ideal race and the faction you prefer don't end up on the same side. Those who seek the duplication of a core race of one faction on the opposite side are fated to be unhappy. And given Void Elves were as close to a Blood Elf as they are whilst still respecting those boundaries, given that the headcanon roleplay Danuser said is perfectly fine would allow you to roleplay a Void Elf who was a former Silver Covenant member, the continuing rejection of Void Elves as the high elves of the Alliance (which is what they are) drains sympathy entirely.
Plenty of the demands for the Alliance will be met. Longer tails on Draenei, multiple ethnicities on Humans, Dwarven tattoos, maybe even Worgen tails. But you are already setting up a betrayal narrative where Blood Elves will get blue eyes (at this point looking to be a done deal considering a tweet Danuser recently liked of someone specifically mentioning how excited they were for blue eyed Blood Elves as part of the customization improvements) and Void Elves don't get the pristine lily white skin tones that will apparently make them acceptable (because it's about the lore, not the aesthetic, right?).
So the Alliance will get plenty of what they in general asked for. They probably won't get what you specifically asked for, but that isn't faction favoritism when what you are asking for is wholly unreasonable.
- - - Updated - - -
Which is of course the pro High Elf method of dealing with detractors. Portray it as killjoys out to ruin the fun of a small group who just want to play their favourite race on their favourite faction.
At least you acknowledge the demand is for the aesthetic of a fair skinned elf rather than retreating to the fig leaf of 'it's the lore, honest!' which hardly anyone believes of the majority of those seeking high elves.
Faction diversity matters. Faction integrity matters. Faction identity matters. Faction matters. Duplicating a core race of one faction to the other undermines that faction. Especially when said race happens, not coincidentally, to be the most popular race in that faction and the most popular race in the game.
Whilst it is seemingly easier to argue for more options rather than defend abstract concepts such as the importance of factions, the argument must still be made. If you don't like the limitations factions impose upon, argue for the removal of those factions or at least cross faction grouping so you can play a blue eyed Blood Elf with Alliance friends. It's an approach that doesn't single out the Horde's most popular race for cross-faction duplication and allows everyone to play with everyone.