This is true in a general sense but they build multiple at a time so it when construction starts on a specific ship depends on the build order and how many are being built at once. It's further complicated by there being multiple shipyards involved, as Neptun Werft builds the floating engine room units for large ships at both Meyer Werft and Meyer Turku.
Royal Caribbean's Odyssey of the Seas was recently floated out of Meyer Werft's hall 6, which means that construction of the first Disney Wish mega block can soon begin. The Wish floating engine room unit is now visible on
Meyer Werft's webcams.
Hopefully Disney will release more information about the ship's unique features and initial itineraries in the next few months. The (fleetwide) deployments could be quite interesting because
DCL is now overcommitted to ports for 2023-2024 following the delay of the 6th and 7th ships.