Whyalla is connected to the main Moonta to Adelaide gas pipeline...

Whyalla is connected to the main Moonta to Adelaide gas pipeline so I guess they could've gone with methane pyrolysis if Hazer had been a year or two ahead of where they are now. It would also save them the cost of building a second desalination plant to provide fresh water for electrolysis.
However the SA gov is ideologically all in on renewables so the economics of methane pyrolysis using natural gas feedstock wouldn't have mattered.

Sadly, both sides of government failed to reserve some of our gas production for domestic use resulting in us (except for WA) paying 4x the price of domestic gas in the USA and Canada. Apparently its the too hard basket to fix that.
Now the Libs want to build 7 nuclear reactors if they get in and dont seem very interested in Hydrogen.

With $8 billion funding for green/electrolysis hydrogen and self inflicted expensive gas feedstock in Australia I'm not expecting too many Hazer plants here while those disincentives remain in place.