I don’t agree with you about the FOSS conclusion you made, because although sub-licensing MIT is valid, it contradicts the spirit of open source. Also, FYI, the Lerna license has returned to vanilla MIT. You might want to update the article.
https://github.com/lerna/lerna/commit/37642a066ed0243d6312240c49c635c3431a989b
Oh wow. Looks like this story deserves a whole article of its own. https://github.com/lerna/lerna/pull/1633
If only I had the time to write it...
is not so bad.