In the backstory of the reimagined Westworld of Lisa Joy and Jonathan Nolan, the question of whether the hosts are sentient takes many decades within the show, and isn’t answered in the affirmative until they are able to bypass their original programming and create their own narratives and determine their own future. In other words, sentience is achieved when one fulfills the criteria for self-actualization. To do this in the story, the hosts have to become conscious of their consciousness through a long, drawn out process of self-exploration and discovery ("The Maze") that puts them on the path to what can only be described as spiritual transcendence from death ("The Door"). Have we seen any evidence that an AI even has the capacity for self-awareness? I think it’s highly unlikely.