That information is completely wrong. Bella and Fantastica have assigned times. There are 3 seatings, MSC considers the first 2 early and the other late. If you request early they will attempt to assign you to either the 5:30 or 7:30 seating as they see fit but it is not guaranteed, you could still get late..
We did the Seaside in May and got the earliest time, we had to arrive at the dining room at 5:15. We attempted to change it as that is way to early for us but had no luck. The problem with 3 seatings is the majority want the 7:30 slot. Few want to be getting ready for dinner at 4pm and most have no interest in the 9:30 seating especially when the service time is close to 2 hours.