Some light I can shed on this, right up my alley it is...
If they were moving/relocating the transformer they would have already started the new pad (transformer Uniculvert) with conduits in place through to the new switchboard location. Energex will not even consider any works until this is done well in advance, total process from start to finish on our last transformer was 6 months, and we had to wait 3 months from when we were ready onsite with everything in place.
That being said, there could be a switchboard upgrade happening which would require more conduits to be installed to the current transformer location, and there is a somewhat easy way to tell this.
If anyone is at the park looking through fences as we all do, look for an electrical "Pit". You would walk over them all the time through the city and may have never noticed them, if there are new pits int he ground then the conduit works have been completed already.
I would, as a GUESS only, think that considering the good weather over the footing install stage, we would start to see parts arrive end of March for an April vertical start. This would allow most of the supports and track to be complete by end of May, wiring and systems in through June/July with testing starting in August for a September opening.
Also we now have to consider that the testing will be a lot more scrutinized after the Dreamworld tragedy, so this may have been allowed for as well, in my own opinion.