if you don't know why it died, then i wouldn't eat it. if you saw it happen and know what did it, then it may be okay. you just don't want to eat tainted meat.
to the person with the unintentional meat birds, here's an option. see if you can put up a sign at the feed store and give them away to someone else and then get layers for yourself.
you will just be heartbroken when these get to age. i don't think if you feel so strongly about it that you should process them. but, they will die. they are bred to.
please consider getting some who are layers. they will live a nice long life for you and you will really enjoy raising them and taking care of them.
if you plan to take care of the meat birds and see them flourish, honey, they won't. it's like you bought a dog that someone told you was a cat. two very different things.
take care and good luck