Cyberpunk

In my opinion the whole "Deckard's actually a replicant" thing ruins an important part of the movie: the juxtaposition of Roy as a machine that's a man vs Deckard who is a man that's a machine. Deckard unquestioningly hunts and murders replicants without remorse, robotically going through the motions, at least until he gets to know a pretty one. Roy murders people in a passionate, angry way, but in the end decides to grant mercy to Deckard, someone he should hate. This act of mercy breaks through Deckard's shell, and restores his humanity to him. If Deckard is a replicant the whole time, it ruins his character arc imo.

I see it as a Lady or the Tiger situation. In fiction we generally expect the rules to come out ( magic A = magic A ) and then be consistently followed. But Dick is notorious for subverting or applying recursion to the same reality-altering notion.

We've seen this happen in other Dick stories. In impostor for example, Spence Olham is triggered by realizing he is not human.

If Deckard is a replicant it is possible he's not aware of his inhuman status and that neither are his fellow officers. Even Rachael brought up the point that the hunters are not expected to get tested, themselves.