When new ministers come into power, or take over a new portfolio, departments, crown entities and SOEs produce “Briefings for the Incoming Minister”. These are colloquially known by their acronym as Bims.
These briefings tend to be a primer on departments, current work, upcoming issues and projects and so on.
The way they are written and what they include varies tremendously.
If KiwiRail had perhaps sold it as more of a ports project, with broader uses than just its own ferries, maybe it could have been retained. After all, given the ferries contract was locked in prior to the global inflation surge, the ships themselves probably represent pretty good value.