Well, sorry for performing a bump, but I just found out something from the game (valid proof (to an extent))... thought I'd bump a thread instead of creating another.
So, you guys are saying about how Ellie would've wanted to die for the cure because of survivor's guilt and so on? Yeah? Well...
(spoilers... even if the thread title talks about the ending, I'll just say spoilers in case.)
...in the University-level near the end of Fall, after you get inside the science building, you can go to a room, which triggers a discussion:
Ellie: "You think it'll hurt?"
Ellie: "Taking the cure from me. You think it'll hurt?"
Joel: "Nah, they're probably gonna just... take some blood, that's all. It won't hurt."
While not being exceptionally valid proof, but proof to an extent that Ellie didn't know about the surgery/she would die in the first place. It also took place after the deaths of Sam and Tess (and Riley), which were the main topic of Ellie's "rant" in the ending.