There’s no telling in what way they may change it or add to it in the fine print. You very well may be agreeing to take a much lower salary going forward. While you don’t have to agree to take a reduced salary, they can still get rid of you. You may even be agreeing to taking less vacation time.
Read your documents carefully. One way they’ll really get what they want. A very tight deadline on “ticking that box”. Heaven forbid there’s enough time for you to let an employment lawyer read anything you’re supposed to sign.