Walt Bulander, expanding your list:
Cousances has been acquired by Le Creuset, the brand is still alive but is not longer an independant producer.
Lodge has an new enameled line that I believe is manufactured in China.
Chefmate (sold mostly by Target, has enameled and plain cast iron) is made in China.
IKEA has a cast iron cookware line called Senior (6 items) that is produced in France.
Tramontina sells enameled cast iron items, produced in Brazil and China.
I believe yout theory has validity, but relative to manufacturing processes. Tanks and most arms are made out of steel, not iron.
After both wars, foundries became extremely efficient and they needed to produce items to generate employment too. Some regions like Liege in Belgium and the Rhur in Germany were legendary for the amount of cast iron they used to produce.