Elune's arrival didn't attract the attention of the Highborne, and no one even knew that she had appeared.
Over the following period of time, when the Highborne discovered that Tyrande's divine protection always existed and they couldn't do anything to her, they gradually lost interest in her. Azshara never mentioned getting Tyrande to be her maid again. The Highborne only imprisoned her and didn't let her leave before mostly stopping paying attention to her.
