You can request it, but it's not guaranteed that you will get it! Unless you are a conceirge guest, and I think they are mostly able to get what they request.
If you do want to request it, then you can either call DCL directly before your cruise, or request it through your TA, or you can wait until you get on board to make the request. There is usually a time and place set up to go to make these changes on board. HTH!
GET UP TO A $1000 SHIPBOARD CREDIT AND AN EXCLUSIVE GIFT!
If you make your Disney Cruise Line reservation with Dreams Unlimited Travel you’ll receive these incredible shipboard credits to spend on your cruise!