Being the nerd I am, I would’ve preferred some dialogue between the two. But alas, I understand the limitations of WoW’s in-game narrative and dialogue.
Do you really believe Alleria falls into that category? I think she just needed time to understand the current events.
Let me explain why I have a soft spot for Alleria. Revealing my age a bit here, one of my first computer games was Warcraft II, including its expansion, Beyond the Dark Portal. This game introduced, to my knowledge, the franchise’s first female hero: Alleria, the High Elf Ranger Commander. As a young gamer, she was a symbol of awe to me – a hero who joined forces with the Alliance to venture through the Dark Portal and protect the world from an impending invasion, ultimately sealing the portal from Draenor’s side.
That experience formed a pivotal gaming memory for me. When The Burning Crusade was released, I was thrilled at the prospect of reuniting with Alleria in Outland, though that reunion never happened – Khadgar was a fine substitute, though!
Fast forward to the Legion expansion, and the excitement of finally meeting my childhood hero was overwhelming. Despite the added layers of her story in external media and her connection to the Void, she remained one of Azeroth’s greatest pre-Warcraft III heroes. She’s not like Daelin Proudmoore, who was driven by xenophobia and warmongering. Alleria was a true hero and a fellow Quel’dorei.
As I mentioned, she returned to a vastly changed world, and it’s understandable that she came back with outdated views. The (FORMER/OLD) Orcish Horde had committed atrocities against Elves, Humans, and Dwarves – it was a harsh reality to come back to. But as she reintegrated into society, she seemed to let go of past animosities.
So no, Alleria is definitely not a Daelin!
PS: Last Edit, I SWEAR! 
She’s standing RIGHT next to Thrall in the Key Art…