I believe the director himself said that Deckard was a replicant. Also, a clue that was in a scene left out of the movie was where the two were traveling through the countryside after their escape from the city when she says to Deckard “We were made for each other”.
I’ve gone all through my special five-disc set for Blade runner and all the commentary, and I didn’t pick up on that. I think someone is “stretching it” a bit ... :-) ...
Oh ... and by the way ... that “ending” that was put in the original movie theater version of Blade Runner, is something that Ridley said he would not have put in there! But, at that time, he didn’t have control over it. And in the later Director’s Cut, he made his changes to “the way it should have been”.