I was very apprehensive about going to Moon Palace because I knew most restaurants were buffet only, and I wasn't sure how well the servers could speak English. I called and email ahead, and while it took several times, I finally got someone who said to find her when I checked in. I believe she was with Public Relations.
It took a while to track her down, but when I finally did, she created a dining card for me in Spanish and sent an email to all the restaurant managers to let them know my issue.
I did still have some trouble though because I had to track people down for buffet meals to see what on the buffet was ok, and because of limited English, it was hard to understand what they were telling me. Not all of the meals were great - some of the extra scared people still gave me the dreaded pile of lettuce with oil and vinegar, or dry un seasoned meat with a side of dry unseasoned veggies.
However, I did not get sick while I was there, so I suppose I can't complain too much. I also brought in packaged food for backup snacks. If you do this, I would recommend also having a note from your doctor for customs.
I went to Moon Palace because my sister in law got married there - I didn't choose it - and while they did their best to take care of me and I didn't get sick, it did feel like going to a different restaurant every night, re-explaining everything, and being a bit stressed about it. I would not go back by choice.