That is funny actually because people made a big deal about it, so when you are the president and have people paying attention to what you wear that gives you another reason to just stick to one good choice.
My source was this article, maybe Obama doesn't always follow his own advice:
https://www.fastcompany.com/3026265/work-smart/always-wear-t...
Unless he just means "two button, notch lapel", but that's not really one kind of suit.