Glad I'm not the only one who thought it was extremely out of character. If Larian wants to give us a peace offering, they're gonna have to do better than this.
But I still doubt that they ever will.
In every companion's story, the player has agency in how things unfold, EXCEPT for Karlach's story. It literally makes no difference if we never even found her by the river, she still only has the same options for her future than if we DO meet her and run around the Sword Coast trying to fix her engine. And this didn't change that.
