Gratuitous images by each story, slow enough to load that it benefits from a cutesy loading spinner, cookies for tailored marketing, email signup box after the 10th story, fat banner that uses the hamburger menu icon but doesn’t trust it to be communicative enough so also has “Menu” in text on the button... That’s...not a Hacker News for X.
I agree with your larger point but in a different way — Hacker News is not defined by UI, but community. I’m sure that there is a Hacker News for auto out there already, I’d guess it’s a myBB forum.
The HN community is of course fundamental, but HN is very much defined by its UI.