[SPOILER] Did she tell him?

[Oscar House]

Yeah, she already explained how it works after

Spoiler below!

the swap from Simon-2 to Simon-3.

Computer: Copy Completed.
Simon-2: There must be something wrong. Can't you run a diagnosis or something? Catherine...
Simon-3: What was that?
Catherine: No, I... it's just...
Simon-3: Why was it still talking?
Catherine: It's the same. Like before.
Simon-3: Catherine. Why was he still talking?
Catherine: That's how it works. You know that.
Simon-3: What do you mean?!
Catherine: You know it's not magic. You were copied. The sleeping Simon in the seat was copied... and now you are here. Just like Simon lived on in Toronto.
Simon-3: Goddamn you Cath. Two Simons? There can't be two Simons!
Catherine: What did you think would happen?!
Simon-3: That you were going to take my mind and put it in to the other body. Like a brain transplant.
Catherine: I'm sorry. It wouldn't work that way.
Simon-3: You realize how messed up this is?
Catherine: Please, I didn't mean to upset--
Simon-3: How did you expect me to react to this shit?
Catherine: Please, stop.
Simon-3: You're fucking disgusting!