My understanding is that if the food is easily swallow sized, they may unintentionally crunch as they maneuver the food around their mouths to position it to be swallowed, but not out of necessity. If the food is larger, sure they'll break it up so they can swallow it easier. But by nature, cats aren't animals that need to chew food for grinding and digestive purposes (like animals that have flat/grinding molars.) As long as they can swallow it, they don't need to chew.