I'll take the bet. Remember, the Oasis began being formulated in 2003...7 years ago. If RCI has another "bigger" idea floating among the braintrust they haven't tipped their hand yet. Granted, they didn't talk about Project Genesis until 2006, but at least at that time the buzz words at RCI headquarters were "game over" (Bill Wright's words on the Freedom inaugural cruise I was on).
But, I might be wrong given another aspect that I just remembered. Shipyards need to be building new ships simply to keep the skills of the craft and tribal knowledge of shipbuilding alive. They just can't walk away and then 5 years later decide to build a more innovative ship by hiring from the local trade schools. This is a problem that faces U.S. builders of war ships.