It is not a question of necessity but of money. Is the Netherlands going to be richer in this scenario? Will the pacifist lobby be less strong? The chances of the Netherlands being able to fund a fleet based around battleships big enough to matter are pretty small.In almost any TL with some version of a CP victory the war is over but the peace is not as outwardly settled. Each great power and the lesser powers will need to remain armed in some better measure. The alliances will remain and relationships cross-cut. The Dutch hang between Germany and Britain, their greatest threat is Japan, a British ally, they pose a threat to Australia, yet Dutch oil is part of the British economic sphere. I do not think they need a large fleet but do need to begin building towards a more complex naval capability to defend the DEI far away. The true threat may be 20 plus years away but one builds a navy over decades. A single big ship could be where the Dutch learn. The same applies to a lot of other navies.