I would say Calia is less aligned with the horde, and more aligned with the people of Lordaeron. There's a huge power vacuum right now, and she is technically their queen. And Valeera is probably just backing up Calia, since she is Anduin's friend and was under his protection. Personally I want to look closer to see if there's any slight awkwardness between Calia and Bolvar. Their possible relationship has yet to be confirmed as real or fake, and if true we might not even see it here since its supposed to be secret.