Just to put a nail on it, a previous commenter above spells it out
“And some of those simpler solutions do come from the dynamic programming world. For example, ‘You can then go further and remove the more primitive operations, only allowing access to the higher level abstractions,’ is another excellent way to make illegal states unrepresentable. And you don't need shiny new programming languages or rocket powered type systems to do it. I was really rather disappointed that that section of the article gave a nod to Dijkstra, but completely failed to mention Alan Kay's The Early History of Smalltalk[1], which was, to an approximation, several thousand words' worth of grinding away on that point.”
So I feel like maybe we all were confused by what the article was suggesting, if indeed it suggested anything concrete at all.
1. http://worrydream.com/EarlyHistoryOfSmalltalk/