Princess Cruises Takes Sanctuary Collection to Five Royal Class Ships, Royal Princess Bookable Now
If you are booked in a Reserve Collection stateroom on Royal Princess, you will be upgraded to the Sanctuary Collection automatically at no extra cost, but without the Princess Premier package that new bookings receive. If you want that package, watch the on-sale dates: November 5 for Regal Princess, December 4 for Discovery Princess, December 10 for Sky Princess and December 17 for Enchanted Princess. If you already hold a booking on one of those four ships, ask Princess whether it will change. Because refurbishment may happen during voyages, also ask whether any onboard spaces will be unavailable on your sailing.
My read is that Princess is turning Sanctuary into a fleet-wide premium tier rather than a two-ship experiment. Moving it from Sun Princess and Star Princess to five Royal Class ships as phase one of a multi-year modernization suggests the line sees demand worth chasing. The staggered on-sale dates, November 5 for Regal Princess through December 17 for Enchanted Princess, look designed to pace bookings ship by ship. The winners are Royal Princess Reserve Collection guests, who get a free upgrade. The wry twist is that they miss the Princess Premier package that new bookers get, which covers premium drinks, specialty dining, WiFi and gratuities. Existing bookers on the other four ships are left waiting, because Princess has not said what happens to them. It also has not said whether dry docks are needed, so work could happen mid-voyage and close some spaces. In your shoes, I would ask about construction before booking and price the Premier package against what you would spend onboard anyway.