As others have pointed out, Andrey Sitnik only added the mention after the twitter thread blew up.

I wouldn't be so sure of that. Most of the world's copyright laws follow the Berne Convention, which in addition to the economic rights that US copyright law provides also provides "moral" rights including the right of attribution.

The US sort of half-heartedly added moral rights about 30 years ago in order to join Berne, but they are limited mostly to works of visual arts and would not apply to code.

They are not so limited in most of the rest of the world. Furthermore in much of the world (such as most of Europe) an author cannot waive or assign their moral rights and so any license term that purports to do so would be invalid in those places.

Even if I was the kind of person who would want to misattribute someone else's work as my own, unless I was very very sure that I only had to worry about US copyright law I would tread very carefully.

MIT requires copies to retain the original copyright notice and license info.