It seems to resolve against 1.1.1.1 but not 8.8.8.8.

    $ dig www.hackingbutlegal.com @1.1.1.1

    ...
    www.hackingbutlegal.com. 1730 IN CNAME target.substack-custom-domains.com.
    ...

It's working now (8.8.8.8) but definitely wasn't earlier. The substack subscribe popover says it was launched 5 hours ago (which seems odd since hn has links from 36 days ago and whois says it was registered 2 years ago) but maybe that's got something to do with it.

https://news.ycombinator.com/from?site=hackingbutlegal.com

Maybe a substack bug? Otherwise that is pretty shady since HN link records are reliable.