I think you're missing my points.
Why reskin anything? The current high elf model is exactly appropriate for the race. It's the same as the blood elf because they are the same species. Blood and high elves are separated by nothing more than a few years of sociopolitical disagreement.a simple reskin wouldn't be any good since they're not allied with the Horde (which is not a problem for, say, Dark Iron dwarves)
Even if high elves are important to the story right now, that doesn't mean they have to become playable in the future. Mogu are pretty important to the story right now, that doesn't mean we're gonna see them as a playable race. I see nothing so compelling anywhere in lore right now that says high elves need to be playable.
Now, I can see Blizzard possibly going in a direction like what the OP discussed. Creating some radically new lore would that gives reason to transform some segment of the high elf population would be...controversial, to say the least. But it could also be a way to tell a new story, tied to old lore that a small number of players are very interested in.
I love these creative speculation threads as much as the next geek, but let's be honest: player ideas for new races and classes are not even background noise for Blizzard. PvE balance, PvP balance, content creation, content tuning, etc., etc., etc., occupies nearly all the feedback they take in from their players.