This was discussed in the thread a couple days ago about board game rulebook design. I had a similar question (https://news.ycombinator.com/item?id=42302038 - although I phrased it more like wondering if Procida had been ripped off) and got some insightful replies.
In short: it looks identical because it's substantially his work, that he did while employed there. In fact, he's the one giving the talk in the PyCon Australia video there.
I actually find the contrasting approaches (see discussion elsethread about the terminology used in the diagram) helpful and it's always good to have historical context.
I agree that the Divio site would be well-served by directing folks to/acknowledging the newer site (as the newer site does).