And that was weird at the time as well. Maybe there’s something I’m missing because I only looked at the first quest you get to talk to her and the quest where you get her as a champion.
But while BFA at least has a token acknowledgement that she needs a real reason to join a faction that she had no established loyalty to, Legion just treats that apparent affiliation as obvious and unspoken. There’s literally no given reason why this previously non-Horde character is suddenly treated as being a Horde character.
I said this earlier, but this is perhaps an even worse example. Thanks to the lack of notable rogue characters, it seems like they literally just went down a list of rogues and picked a name without regard for what had been previously established about that character.