The question, "is Harrison Ford's Deckard a Replicant or not?" is one of the most hotly debated topics in movie fandom, alongside "who is the best Starfleet captain?", and "how the hell did that T-Rex sneak up on people in JURASSIC PARK?". For many, people assumed it would be a question that would never be answered definitively. Hell, BLADE RUNNER 2049 director Denis Villeneuve was quoted as saying "not necessarily" when the question was brought up to him.
However, that wasn't technically a "no", so when producer Ridley Scott (advocate of the "Deckard is a Replicant" camp, and original BLADE RUNNER director) had an interview with IGN, this is how he answered when the question came up:
Oh, it was always my thesis theory…Harrison (Ford), he was never — I don’t remember, actually. I think Harrison was going, ‘Uh, I don’t know about that.’ I said, ‘But you have to be, because Gaff, who leaves a trail of origami everywhere, will leave you a little piece of origami at the end of the movie to say, ‘I’ve been here, I left her alive, and I can’t resist letting you know what’s in your most private thoughts when you get drunk is a fucking unicorn!’ ‘ Right? So, I love Beavis and Butthead, so what should follow that is ‘Duh.’ So now it will be revealed (in the sequel), one way or the other.
I know, cool, we're going to find out the answer in the new film (and judging by this quote and other interviews, it seems clear where the answer will lie). However, I'm most intrigued that Ridley Scott seems to be a fan of BEAVIS AND BUTT-HEAD, which is awesome.
Either way, BLADE RUNNER 2049 will hit theaters October 5th.