Title of the article is "How…", not "Why…", and "why" is not discussed. (My understanding is that the "why" is "because the implementation acted that way without an official guarantee, and folks depended on the implementation detail, so it became guaranteed.)
I don't think this is the "why". What you're depicting is what happened in JavaScript. Dictionary keys in Python always had that (to me) annoying property that they preserved insertion order until they don't. I'd frankly much prefer if they'd always be iterated in random order each time they're traversed.
I'd love to see the results of mandating a random order dict impl at an actual company/org (but hate to be forced to participate). Hopefully you hired developers who really like to write sorting algos.
The URL for the post includes "why" (en-why-is-python-ordereddict-ordered), so I suppose the title of the article was updated after the HN post was created. The site's native language is Chinese and I'm guessing the post was translated via automation. In fact, if you run the article through an automated translation service (Google Translate), it reproduces the "Why" title.
