And the book, Catching Fire, mentioned in the article and from which most of the info is gleaned is from 2010. The scholar in the article, Richard Wrangham, wrote the book.
Sapiens by Yuval Noah Harari doesn't push the domestication of fire as far back as 1.8 million years as Wrangham does but it does note that the chimpanzee brain uses 6% of the body's energy at rest, while according to the article "A human body at rest devotes roughly one-fifth of its energy to the brain". The hypothesis is that only cooking could have provided this boost. Shorter gut, bigger brain. It's a fascinating conjecture. The question is, did we develop sophisticated language before domesticating fire or vice-versa. Perhaps the synthesised creation myths of all the world's cultures and religions could provide a clue?