This is totally wrong. The body can also slow down your metabolism, twitch less, think slower (if you had read the article you'd see this is addressed), decrease the effectiveness of your organs, not to mention "eat" some of your nonfat muscle mass.
The people advancing the CICO idea have obviously never struggled with their weight. It is super clear to me as a person who has bounced back and forth between fit to overweight for my entire adult life that there is nothing I could ever do to be as "skinny" as the skinny people I know, all of whom eat and drink way more than me, and usually don't exercise at all.
CICO is not real advice, it's telling people to develop eating disorders, i.e. starve themselves. And for what? To bolster the ego of you and the ~60% of people who are naturally less likely to accumulate body fat, who like to believe they are just smarter or know something about nutrition that people like me don't. But it's exactly the opposite. I know more about nutrition than any of my skinny friends. Social pressure has demanded that I do so. It doesn't actually help, and the smugness of commenters on HN doesn't either.