Gentle reminder; Void Elves share more in common with the Blood Elves than High Elves do. The Ren’dorei were Blood Elves only a few months ago, and never wanted to be anything else. They were exiled, which forced them into renaming themselves. If not for that, Umbric and his followers would still be regular Sin’dorei, fighting and living for the Horde.
High Elves, even after all these years, still haven’t and probably never will become Sin’dorei. What reason do they have for rejecting their ideals and philosophy? None. Clearly there is still some kind of conflict between the two groups.
The last bit of information we have on their views for each other is from the “THree sisters” comic (I think that’s what it’s called?), where Vereesa claims that the Blood Elves can still be redeemed.
Our last interactions with the High Elves has been on the Alliance side, too.