Any discussion of Aerith's death in the Remake has to consider not only whether she will die, but whether she needs to die. To put it another way, when asking whether she's a willing sacrifice, we need to consider both whether she's willing (i.e., has foreknowledge) and whether she's a sacrifice: that is, something that needs to be given up in order for something else to be obtained.
Leaving aside the question of her willingness for the moment, I'd argue that she was not a sacrifice. She did not need to die in order for Sephiroth to be defeated and the Planet to be saved. Some people are of the opinion that it's only because she's in the Lifestream that the Planet decides to muster its own defences to drive off Meteor; somehow, she persuades the Planet to do this or bends it to her will. That's certainly a possible interpretation, but there's no firm evidence either way.
The story of how Sakugichi's mother died while they were making this game, and the effect that her loss had on him, has always coloured my view of Aerith's death. Death is cruel, abrupt, and meaningless; life is precious. Aerith's death isn't beautiful. It serves no purpose. It brings the party no closer to their goals, and robs them of their healer. The Planet is arbitrary and indifferent, concerned only with its own preservation. Yet despite all this, the party struggles on, creating their own purpose and meaning, and figuring out what it is that drives each of them personally to keep fighting.
I prefer this interpretation because the message resonates for me personally.
Aerith may forsee her fate. Still, knowing how and where you will die doesn't automatically mean your death is meaningful. It may be necessary in the sense that everything is predetermined, while not also necessary in the sense that it achieves nothing.
This time around, the designers may decide that Aerith's death is necessary in order to save the planet. That will be as big a change as deciding to make her go willingly to a death she has foreseen.