If Auckland is becoming a city based around public transport nodes why is the Unitary Plan releasing so much rural land for urbanisation on the edge of the city?

Stat’s NZ’s official population growth figures have exceeded their High projections for many decades in Auckland.

It is true that at times Auckland’s population growth as a whole has exceeded the Stats high population projections and at other times it hasn’t. How is this relevant to the projections the Council has created regarding CBD population and employment?

Which projections? The City Centre Future Access Study which reached this conclusion assumed a much higher growth rate of population and employment in Auckland's CBD than has been the case historically. It also assumed that the CBD will grow faster in the future than Auckland as a whole. In the past employment in the CBD has grown at about the same rate as Auckland as a whole.

I think this post highlights the difficulties inherent in transport project evaluation. Transport project evaluation requires you to make assumptions about the future and what benefits to include and how to count them. Wider Economic Benefits (WEB) are especially tricky as they're triggered by people's responses to the improvement in access that a new transport project provides. Therefore the chain of assumptions is longer and hence divergence between different analyses is more likely.
The whole process is then overlaid with politicians and others deciding they want a project which can then result in assumptions that are favourable to the project.

A few full trains doesn't justify building the CRL. There may be more cost efficient ways of transporting these people. Rail has a much higher level of subsidy than bus travel, but it's unclear why it's deserving of this high level of subsidy.
The Council is doing more than prepatory works, my understanding is that they are starting construction of the cut and cover tunnel in Albert St next year.
If the Council's assumptions about the CRL leading to a much higher rate of employment and population growth in the CBD are correct (this is partly how they get a higher benefit/cost ratio than the government) then CBD property values are likely to rise as a result; I'm surprised no one has suggested taxing or rating this value uplift. This is commonly done overseas.

The article appears to tacitly accept that the Council is spending wisely. The biggest project is the City Rail Link which the Council is commencing construction of next year. My understanding is that no business case has been done for it yet. It seems odd to be starting construction before a full evaluation of the project, especially where the Council's own ten year plan projected that the fare box will only cover a small fraction of the costs (largely debt servicing) with ratepayers or taxpayers having to pick up the rest. Where is the justification for this?