Yes, it is true on the Fantasy too. Same timing as on the Dream. The Micky show and the Jack Sparrow show were very different shows. Both were fun. Nothing Earth-shattering, but good Disney excitement.
After the fireworks, there is a "pirate dance party" on the main deck. It is at this time, DURING the dance party, that the Pirate buffet happens in Cabanas. The buffet only lasts like 45 minutes, so it is possible people miss the buffet because they stay for the dance party and don't know it is happening.
The buffet itself isn't as extravagant as late night buffets of old on other lines, but it is fun. Lots of desserts. My sons liked the make your own taco bar, though many people got confused by it. The taco shells and meat are in one place, the "fixings" are in the next spot, with some of the desserts. So it kinds a looks like tacos with no toppings, and separately, desserts with guacamole and cheese and sour cream.
I'll also say that I didn't find it to be quite as crowded as I expected. It was crowded, but not crazy, and it ebbed and flowed. So if one part was too busy at a given moment, we ate what we got from other parts of it and then went back to the area that had been too crowded.