They can still opt out of this binding contract but Early Decision (ED) is not for everyone especially students who need financial aid. But some apply ED anyway to increase their chances of acceptance without them knowing that this comes at a price: less or zero financial aid. Recommendation? If a students needs financial aid, they should not apply ED but instead apply Early Action, Regular Decision, or Rolling Admissions. This is FINANCIAL AID 101.
Read up on this article on how applying early can affect your chances to obtain financial aid: