Alfonso Cuarón’s upcoming Apple TV series “Ascension” has added three new series regulars. Variety has learned that Amanda Plummer (“Run,” “Butterfly Kiss”), Christopher Chung (“Slow Horses,” “My Brilliant Career”) and T’Nia Miller (“The Haunting of Bly Manor,” “VisionQuest”) have all been cast in the series. Exact character details are being kept under wraps. As previously.