Thats wrong. If memory serves they are never told what they are and regular, day to day human life isnt something they know of, are taught or follow. They are, just as Batty says in the movie, slaves. They serve a purpose and do jobs. The "new" experimental replicants are given memories. To add more "WTF?" to the mix, Tyrell is a replicant, he was filmed as a replciant. The parts that were never included with any cut of the film is the real Tyrell, and this is even in the Future Noir book and the filming script, is kept in suspended animation awaiting a cure for some disease. His condition is a complete secret for the sake of the control of the corporation. But, Darrel's other brother Darrel accidentally kills him while maintaining his suspended animation system. That job is why Darrel and his other brother Darrel have direct access to Tyrell in both human and replicant form. Batty, and I forget how, knows this. In the script prior to where Harrison Ford was involved and while Dustin Hoffman was still on as Deckard, Hoffman demanded parts of this scene be taken out. This was after Batty kills Tyrell, then he would go and kill his family. The ONLY reason he kills Tyrell is because he knows Tyrell is a replicant.
To sum it up, replicants do not know they are replicants. If this ends up the prequel story, ill be a happy man: Batty found out he is a replicant while on an off world colony base, banded together, organized an uprising and escaped with a handful of others. His plan isnt to save, free or exonerate replicants. His intention is for more life, screw everyone else as they are expendable although he obviously becomes close to the girls.