Don't get me wrong, I'm really happy to see Alleria being part of the Alliance. Logical and pragmatical though I would have prefered her to be more neutral toward the blood elves only. After all, they are still her people and I can't see her attacking Silvermoon.
But I don't know how it could work(or will work) in BfA ...
We know she's trying to bring the blood elves into the Alliance whereas the knows her sister is warchief of the Horde. So Sylvanas will likely consider it as an act of betrayal and will likely reject her. And we also know the Horde will try to secure Stromgarde to defend Silvermoon, which means the Alliance's crusade in Lordaeron will probably reach Quel'Thalas' borders too...
What are your thoughts about it guys ?