Getting rid of people, does not mean less iron ore will be mined and exported. RIO and BHP are heavily into automating the mining and transport of iron ore to reduce costs per tonne, and I imagine FMG is too.
The big-picture driver behind steel production is global urbanisation, which is occurring at the rate of 60 million people a year. Short-term price zigzags occur mainly as an inventory issue for items like finished steel, pig iron and iron ore. Chinese importers control the iron ore inventory, and if it gets too high, they hold back their buying, and the sellers compete to reduce the price. A zag in the zigzag should not be interpreted as the end of the long-term demand for steel. The long-term threat comes from increased global supply, not global demand, and low iron ore prices will choke off some of the supply threats.