I don't believe this is true: the MIT license requires maintaining the MIT license disclaimer in the derived work. AFAICT, you cannot actually relicense MIT cod

I don't believe this is true: the MIT license requires maintaining the MIT license disclaimer in the derived work. AFAICT, you cannot actually relicense MIT code (unless you hold the copyright). You can create a new derived work that contains it, and distribute that work as a whole with a new license, but the MIT code portion of that work will always maintain its license and require distributing the MIT license disclaimer. https://softwarefreedom.org/resources/2007/gpl-non-gpl-collaboration.html https://softwarefreedom.org/resources/2007/gpl-non-gpl-colla... With that being said, for the purposes of the article we are discussing, this distinction may not be meaningful because one can still take an MIT code base proprietary even if the original code doesn't actually get re-licensed.