IANAL either, but I'm pretty sure you are correct. I put it in another comment somewhere, but I'm more upset about not being given a choice to refuse the change rather than the actual change itself. I don't mind signing the waiver at amusement parks, or to buy a car with no warranty. I just want to know what I'm agreeing to, and I don't like folks pulling the rug out from under me or changing the deal.
The situation feels like if I were to drop out of college, I would be given electroshocks until I'd forgotten anything learned in class.