They say they are, but it is possible Clovis is tricking them. I seem to remember that Clovis doesn't always show them their incept photos, that's sometjing that changes each time. So are they human or replicant each new game, like other characters? If so, how do you know when they're a replicant? I don't think it really matters in game, but I am curious.

So, spoilers follow
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Yes, they can either be human or Replicants.
- If they are Replicants, Clovis will *not* show them a picture/ incept photo. They will realize it on their own.
- If they are human, Clovis gives them the picture (which is a fake incept photo)

There's only minor changes in the story.
- If they are human, there's a dialogue variation whereby McCoy suggests that the photo Clovis gave them was doctored.
- If they are Replicant, they'll instead say to McCoy that their memories don't exactly match.

If they are still alive by start of chapter 5, they will be at the moonbus, at the co-pilot seat in the background; they are barely noticable there, and if you take the "McCoy betrays the Replicants at the last moment approach", you'll have to kill them too (otherwise you'll be unable to leave the moonbus).