I just did 2 cruises this year while on keto. It was difficult and depressing but the scale showed I had only gained a pound or two which really helped put me at ease going through that. The article by OP mentions sugar free desserts. I suppose they are but the crust would not be carb free at all, from flour. I did not try those. I only had the 'cheese' plate once or twice as I only care for harder cheeses. The cheese plate also has grapes and one strawberry so it's going to temp you also!
Be careful about soups, after 5 minutes I finally got someone 'in the know' from the back who informed me the pumpkin soup has brown sugar in it on the buffet. All the gravies on meats have starch thickeners, probably cornstarch or flour. Even the meatballs in the dining room have breading filler, I was told. I was able to go to the itallian place and get a bowl full of meat and veggies without pasta. Dinner time was usually grilled chicken and double broccoli and butter with shrimp cocktails appetizer (only using very little cocktail sauce on them, it has sugar). Many times I ate the top of the pizzas. The burger place you can get 2 bacon patties to replace the buns which makes them easier to eat. It was nice to find buttered green beans once or twice on the buffet. The mongolian place didn't argue when I said I didn't want sauce, so that was decent but the line usually wasn't. Breakfast was always in the dining room so I could get honest real eggs sunny side up plus bacon, sausage, ham. The buffet scrambled eggs will be from powder or a liquid carton with fillers.
Stay vigilant about your food and you'll be glad you did later on.