Now this was about 7 years ago, it was on our first trip to Disney & my son got sick (very sick, where we had to go to Urgent Care). Of course that morning we had ADRs at the CRT. I called Disney Dining and said 3 of us would not make it, 2 others in our party were still coming.
They still had to charge us $10 for each person not showing up.
Now this was when CRT was VERY, VERY hard to get in too. I know it is easier to get into now so maybe it was changed.
Just wanted to tell you our experience.
You could call Disney Dining now and see what they can do? It won't hurt.