If an appliance such as an oven or cooktop came with a whip, and a lot of them do, I would expect the appliance to be connected to a J-box and thus "hard wired". If the appliance came with no whip and it was easily disconnected from it's mount and other possible connections, I would have no problem approving a cord and cap type connection. I would not expect to qualify my approval based on a permission in the manufacturer's installation guide. On the other hand, if the instructions said "Do not cord connect" I would support that directive.
