Nightborne belong to the Alliance, not the Horde. Besides, Liadrin showed no sympathy to the nightborne whatsoever.

nesuna-nightwinter:

We might weep, my friend, but…alas…it makes total sense.

Tyrande’s behavior towards Thalyssra and the Shal’dorei has been outright dismissive, even hostile:

Let’s just take the one example from Take Me To Your Leader (Horde), We can very clearly see Tyrande’s mentality (and also Vereesa’s mind you) towards the Nightfallen:

Tyrande Whisperwind

When I let you take the Tears of Elune, I assumed the next time we would see each other would be at the final battle with the Legion.
I did not expect to see you in the company of mana addicts at the footsteps of the city of my birth.
Speak quickly, <race>. I am not in the mood for Thalyssra’s petitions.

Vereesa Windrunner

For the record, I counseled against trusting any Horde in this campaign. I have lost a husband and a King to the treachery of the Horde.
I see no reason to trust you now or ever.

Whereas the Horde…

Lady Liadrin

Few understand the plight of the Nightfallen better than the Sin’dorei. My heart goes out to them.
But Thalyssra must understand that there is a difference between an insurrection and a war.
Until now, her rebels have got by with a few skirmishes here and there. But they have not been hardened by battle as we blood elves have.

Grand Magister Rommath

The Nightwell. An unimaginable font of arcane power. What would have happened to the sin’dorei if we had such a source?…
No matter. We have forged our own destiny. Our glory is our own, and we are no longer slaves to our hungers.
This siege is a momentous occasion, <name>. We stand with long-lost kin, our enemies, against some of the most powerful magi in the world. Our actions will determine the future of all elf-kind.

I love a good-looking elf Ally-side as much as the next Kaldorei RPer…but in this case, Blizzard made the right choice.