Yes they do still the Fantasmic Dessert Buffet. I just sat in the Riverside seating a few days before New Year's Eve. It is totally worth it, because otherwise you are wasting time sitting on the ground hours before the show instead of riding the rides. It's worth it for the seating, but I wouldn't say the desserts are. They are ok, but nothing special. We were given 2 chocolate covered strawberries, 2 macaroons, 2 chocolate covered shortbread cookies and something else which I can't remember right now. Beverages are included as well. When we originally booked the buffet we thought it would have more elaborate desserts, like cakes, pies, cheesecake, etc. However, if I had to do it all over again, I would still pay the money for the seating.
Enjoy the show.