I don't know if this is an intended outcome or not, but here's what I did in my game.
1) Followed the Vailian questline and went to Crookspur. Killed the pirates there and freed both groups of slaves.
2) Went to Ori o Kohiki and spoke to Rusana. She informs me that the Ruataians have taken over the island, which I do not know is intended or not since I was not following the RTC storyline.
3) No matter what choice I select with her, she refuses to talk to me any longer. I cannot read her soul and continue Aloth's quest.
4) Furthermore, it seems intended that I can kill her by poisoning her fruit, but this does not seem to have any reactivity.
I'm not sure if this is a bug, poorly thought out questing or an intended consequence of quests I haven't done. I'd love some input, thanks!