First post! - Extension of the Metroplitan Urban Limit???

So just to set the scene here. Last year in the second year of my planning degree we had some assignments which focused on the Kumeu, Huapai and Waimauku areas.
Part of the assignment was to come up with a plan for the development of the Kumeu-Huapai-Waimauku area based on the assumption that with the continuing growth of Auckland these areas would one day need to be developed further. The majority of the class included ways to reduce unconstrained growth in the area as a way of preserving it.

The image below shows the Auckland metropolitan urban limit which includes the north-western areas of Hobsonville and West Harbour but doesn't include Kumeu, Huapai or Waimauku.

Source: http://www.royalcommission.govt.nz/web/part4/18_boundaries.html

The metropolitan urban limit in Auckland is a tool to reduce urban sprawl and development outside of the defined areas however, when I was in the Kumeu area recently I noticed a number of signs explaining that Watercare Services Ltd are installing wastewater pipes which will service the Kumeu, Huapai and Riverhead areas.

I can't help but see this as the first step towards the Auckland Council extending the MUL.
And, if that is the case, it will surely have many implications on not only the Kumeu area but the rest of Auckland as well.