Being under a kitchen is noisy, but I doubt that is bad because they aren't up all night preparing to feed thousands breakfast, lunch, and dinner in the main dinning room. The fact that they only serve from say 6PM to 10 PM means they should not be loud when you want to sleep.
With that said, I have never been under that kitchen so I am just guessing. You never know. I was under the main kitchen on my Mercury cruise years ago and every morning at about 5 AM is sound like the mixer was coming down the side of the ship to enter our room. Even with ear plugs it would wake me up.