I don’t know how other companies work, but I work at a company that produces a lot of reality TV shows. They definitely have writers that will lead the direction that the shows take (for example challenge ideas for a dating show or maybe bow they deliver hints to a blind customer cooking show) and they’ll have some leading questions in interviews (or even asking to phrase things for more drama if the contestants want to and they usually say yes) but you’d be surprised at how unscripted the ones we produce are.