A lot of folks are asking why would a person commit so early. To me it is easy. There are no guarantees in life, and what if no other offers come? By not taking the "Bird in Hand", the opportunity may fly by. I don't have a problem with players changing their mind. (I must disclose that my son did.) Coaches change their minds all the time. They may not prior to the kid arriving on campus, but plenty change their minds after fall practices, first year, second year, etc.
The player should do what is best for him. If the kid has a change of heart about his commitment, he isn't doing the coach any good by reluctantly honoring his commitment. If I was coaching a team, I wouldn't want a kid that doesn't want to be there.