That 'reveal' is definitely overkill - in a world where shaving off 10s of milliseconds in load time helps engagement, adding 100s of milliseconds of unnecessary pause before content does seem a little silly.

That said, 'has javascript' is a reasonable assumption for most websites these days. Most people outside the HackerNews echo chamber wouldn't dream of turning it off, but then I suppose this blog is aimed at the HackerNews audience (among others).