(Melton line will become part of Metropolitan rail network soon (5-10 years), so I posted here)
The Melbourne Suburban section is for everything within Zones 1 and 2, so you're entirely right in posting here.But that is like 9 years away, the houses would be already be there by the time the station is built. The station can be built at any time not reliant on another project. But it is better the station gets built sooner than later, since when it's built people will use it. Otherwise you let the growth corridor get the housing and then rely on the roads and then more traffic gridlock. There are no restriction when the station is built since it will be needed anyways, it just needs the funding and political support and commitment.
While it makes sense to build stations before they are needed, that is not how it's done in Victoria, as recent history shows us. Look how long it took for Caroline Springs station to be built.
The best best would be it being built at the same time as Melton Electrification, which cannot happen until after the Metro Tunnel is built.