According to the novels, Oola did indeed die because she didn’t want to be near Jabba-she had been raised in her family as a dancer, the daughter of a minor aristocrat, I think, and dance was her life. She was determined to die dancing or something like that. When Bib Fortuna had her kidnapped, there was another Twilek girl with her, Sienn’rha, who somehow meets up with Luke before they get to Jabba’s-Sienn’rha runs off and joins the rebellion, Oola declines and goes to Jabba’s, not trusting Luke.
Jabba just liked having dancing girls around. The fat dancer with six boobs, btw, was sort of like mother hen to all of the other dancers-she was trying to escape someday and get back her cubs. She named two of them Luka and Leia, after Luke and Leia.