The metro station that
@TheRam is talking about is being mooted as part of an extended Westmead - Parramatta - Olympic Park - City line (Metro 2), which is being mooted to maybe being extended through to Oxford St, Moore Park, Zetland and on to Maroubra Junction.
Any new rail system needs turn back and train holding yard facilities. This isn't possible at the city end of this metro project so an extension beyond the city to the east or south east is a must.
Therefore a station at Moore Park is a possibility. It certainly doesn't need to be a white elephant.
Trains could just not stop there when events aren't on, but it would come into its own on event days. It would also compliment the light rail.
The City - Parramatta metro is also going to interchange with the North West rail link which will by 2024 be finished all the way to Bankstown so Moore Park would be accessible to large parts of the population.