Yes, we did this today at lunch. Resort CS places realize that on the DDP you have a mug for your drink so from what we have seen they allow the swap. Pepper Market was fine with it.
Sometimes we grab a bottled juice for our drink and keep it for an in room breakfast the next day while we use our mugs for our drink. Today I swapped my drink for a pastry to keep for a snack after we get back from the parks tonight.
We are here right now and the lady behind one of the food counters at Pepper Market suggested getting a dessert instead of a bottled drink. I had forgotten all about it until she said something!