Or at least definitely that the William storyline is in the past. Early in the season, the "Man in Black" talked about how he opened up the robots in the past and they were all mechanical instead of blood and guts like the modern ones. Dolores was v mechanical when she got stabbed by Logan which indicates it was in the past, back when she was an "old model."
Also there was some other thing about the logos used. When William first comes to Westworld, they are using the "old logo" in the room where he gets his introduction.
