If the Andrews government goes with the cheaper option, we may see new pax cars to replace the N cars or if the government wants to accelerate the regional services timings and replace the loco hauled sets entirely, it may well go with DMU's...similar to VLocity's perhaps.
If they go with a DMU replacement of loco hauled we will likely see a big investment in LX protection...bells and booms at many crossings for the higher operating speeds and a concrete sleeper, heavier rail and signalling upgrade to see an increase in service frequency due to increased patronage which will come with the introduction of new rolling stock.
The elimination of loco hauled and the many rough starts/stops due to many drivers who don't know stretch braking, my gripe in particular on the UP Swan Hill won't be missed by me currently sitting in the ACN.
DMU's definitely ride much smoother overall than loco hauled.
In the future...assuming Victoria gets more freight back on the rails...N Class loco's may get a second lease of life in that arena.