The DA application makes no mention what-so-ever of the Metro station, so any changes by the State Government won't affect the development aside from the obvious impact of NOT have a metro station next door.
Rozelle station or not, what's being built won't be the final route.
www.sydneymetro.nsw.gov.au
The NorthWest Metro (the extention from Rozelle up Victoria Road) was a few stages down the development plan, as is the West Metro and East Metro (or what ever it's called... the one that goes east)
Anyone that has ever been to other Alpha/Beta cities around the world would appreciate how amazing large metro networks are.
Tokyo Metro:
The Tokyo Metro has pretty much eliminated the need for the average Joe to own a car, and it works in tandem with the existing above ground network.
Over time, more and more routes will be added. I personally look forward to the day when a vast metro network extends across sydney, where you can easily get from Rozelle to Bondi, Ryde to the SCG or pretty much anywhere via a fast, underground network.