Your chickens are OK. They do not mourn the loss of their life. They enjoyed being chickens very much, and plan to be chickens again and again. They do not care so much where they are chickens again, though their experience with you has made them decide to be only on farms that allow pastured or free-range chickens from now on. They like being chickens, like laying eggs, like roaming and pecking. They are happy to be chickens now during this time of revolution in the farm industry.
Do not feel badly that they were not locked up, for they were happy in their relaxed atmosphere, and glad to be free so much of the time. They know that few others would have given them so much freedom, and were happy to trade freedom for risk of injury. They have already been reborn this very morning! So do not fret, they are happily cycling through another life where they will be free and joyful, and always in the moments. It was time for you to be chicken-less for a while, to make room in your life further on for more chickens, and more animals.