What ? Alleria also calls Sivermoon her home. Even Lor'Themar describes her as a child of Quel'Thalas. She also says "My people" when she refers to the Blood elves Yet she's Alliance. You're just fooling yourself.
Also the Ghostlands thing isn't canon, I'm sorry.
See Telegrus Rift and the new costumizations options for the Alliance. Alliance Silvermoon elves are a thing.I don't see how the blood elves are slowly going alliance.The high elves as we know them are still largely scattered and doing their own thing. SL might change things though considering the customization development.
Well, that's your opinion.I have to disagree with you there. They knew quel'thalas was in danger and they bailed. They also had the chance to help rebuild it and still didn't do so.
How do you claim it to be home when you've abandoned it during the times they needed you?
The high elves/void elves are also a much smaller force than the blood elves.
We're talking at worst a 9 to 1 ratio.
Some elves in Silvermoon may not still feel Horde in 2020.
But that's not up to you to decide. If Blizzard wants Quel'Thalas to be invaded, it will.If the alliance tries to help that will just start up another warand no one wants it. So I doubt an invasion of quel'thalas will occur.