If Disney follows past practices, it will most likely be a 4 day, and bump the Dream to go to Miami. There is a possibility, it will be the Fantasy that gets the bump, but Disney does pretty good at past practice.
As far as the maiden goes, it will be a stand alone announcement, as when bookings open up. Theyll follow the traditional opening day procedures, where Platinums book 1 day, then gold the next day then silver and everyone else.
Fair warning, the maiden can move dates. They moved the Magic and Wonders a total of 5 times between the 2, and the Fantasys 1 time. If they do what they normally do, the deposit is inline with concierge, where its non refundable and slightly higher. But you can still pay it off over time, but its a shorter time frame to do so. Instead of 18 months it may be 12-15. Theres still a lot of unknowns, mostly due to corona throwing monkey wrenches into the mix. Its still possible that she slips from summer of 22 to Feb of 23. or anywhere in that time frame.