!!!!!!!!!SPOILERS!!!!!!!!
Wait, I don't really get it. Did they use Nick's mind/soul to create the AI of the animatronics or only used his mind to "sync" all the other future animatronics to work properly in the future, which caused his soul to inhabit some of the (perhaps even every) animatronics? Does that "I'm in heaven" in the end mean that Nick's soul eventually accepted his place as an entertainer, bringing happiness to families all over the world, since this is what he secretly wanted all along?