Even if they included tips.... I wonder if that would make crew members happy? As we often pay way more than the suggested tip amounts for the positions that are part of the recommended tipping. But then there are others, like the poolside severs, and the upscale dinning servers or those working in the SPA?
In the end I expect most crewmembers working in TIPPING positions, end up with more than recommended tipping rates. So I could see an issue with crewmembers that are use to sailing on most the
DCL ships where tipping is expected. Key might be only having new hires that aren't aware of how it's done in the rest of the fleet... Adventure might end up offering a different level of service than some have come to expect???
As for soft bookings... Trips to no where just might not appeal to some/many. Disney might have to do as most the other lines sailing for Singapore do, and actually go somewhere... Lot's of room to play with that.