Their blog also seems to rely on JS to render text. I mean, most sessions will have almost no user interactions besides scrolling. Generating the HTML and serving it static seems a no brainer...
My bad, it wasn't visible until I disabled uBlock, requests seem to be caught by the "uBlock filters – Privacy" list. Does the IA actually run the JS and archive the fetched JSON on its own, or does it depend on someone visiting the archive page with their browser to trigger archival of this JSON data?
another reason to stop using SPA and use island base or NO JS web page for informational stuff like forum and discussion. At least displaying of information on the web should NOT depend on JS.
And since their forum does not render without Javascript, it is still not archived on archive.org, and probably not searchable with Bing or Duckduckgo