It's not a question of "accomodating" or not. You see, in a professional kitchen, the Line (where the cooking happens) is set up with certain ingredients & components based on what dishes are on the menu for that meal. This is called Mise en Place. There is a whole set of preperations that goes into setting up the Mise en Place - vegetables that need "prepping", sauces that need to be made, doughs that need to be made & risen or rested etc... The Mise en Place is usually completely different for lunch than it is for dinner. Where there is overlap, you will usually already see that dish on both menus.
The Line is a very compact, efficient portion of the kitchen where the action takes place. Anything extranneous is removed from the area for the sake of efficiency. That includes items not necessary to produce the dinner menu. Those extra items would be in the big walk-ins & pantries out of the way. In some kitchens, even on a different floor than the main kitchen is.
The other issue involved is that in some kitchens, the lunch & dinner staff are 2 different shifts. The dinner staff may not be trained to prepare a lunch item.
Disney goes above & beyond any of the kitchens I worked in to try & accomodate people. It really is hard on the kitchen to expect them to come up with a dish from a different menu if that dish's ingredients are not part of the dinner Mise en Place. In a WDW restaurant, I would assume they are feeding hundreds of people in the dinner hour. The folks in the kitchen are slamming, no doubt about it.
I don't think most people know how a professional kitchen operates & maybe in knowing a little bit about it, your hubby would be just as happy to find something on the dinner menu.
