The bridge was designed with passive provision for a future duplication and space left in the corridor for it, but that can be done without any impact on the station other than temporary changes during construction and realignment of the access roads.
It's a case of passive provision, not an upcoming project high on any agenda.
The platforms are too short to have doors open on all six cars of a double A-City EMU consist. That's no big deal as there are quite a few stations on the Gawler line with that issue and the previous government had the foresight to ensure that the A-City had Selective Door Opening included.
If there's a significant increase in train patronage I think we're more likely to see additional centre cars inserted than orders for more whole three car units to allow regular operation of six car trains.