I was on the DxDDP this past May and chose to dine in a signature restaurant every night. I ate at: California Grill, Narcoosee, Citricos, Jiko, Artist Point, Flying Fish, and Yatchsman. I wore capris and a nice top and felt fine everywhere, except Narcoosee. I swear every woman in there that night was wearing a dress or nice pants. Everwhere else, I saw a wide variety of nice dresses, pants, capris, and shorts. Some people at Jikos, California Grill, Yatchsman, and Flying Fish looked like they had just come directly from the parks in their shorts and t shirts.
About 1 1/2 years ago I made a point of going back to my resort to shower and changed into some nice pants and top for my Artist Point dinner. The lady checking in ahead of me was wearing the exact same outfit I had worn to the parks that day (tan shorts and an Eyeore T, with flip flops). Her son was wearing flowered board shorts and flip flops. Nothing was said to them.
We are going back to Narcoosee in early Sept and this time my mom and I are wearing thin, cool, jersey dresses and my husband will be in kacki pants and buttoned up, collared shirt.