Yes it has large amounts of debt but the article doesn't say how that makes it bankrupt. If you can show that the debt exceeds its asset maybe even when that's not the definition of technical bankruptcy just so you know.
Only Eskom estimates its asset value at 1.3 trillion rand. Most outside Eskom put that figure more realistically between 200 and 300 billion rand. Looking at its debt levels that would make it bankrupt by any definition were it not for it being an SOE.
Ted Bloom probably says it best: “This is just a massive Ponzi scheme waiting to collapse. All Eskom and government are doing is sucking consumers into increased tariffs which, in turn, are used to increase debts to lubricate ongoing corruption at Eskom.”