I feel there are still some mysteries that need answers related to the origin of Henry and how he was used by Brenner to get more children who were like him. Brenner definitely knew some truths because he told Eleven “you will soon find out the truth” while injecting her with the injection to make her unconscious. We don’t know if Eleven will come back to Nevada and work with Dr. Owens and NINA to improve her powers or find more details and secrets about Brenner’s research.