I tried two different VPNs, currently on NordVPN ... no issue accessing Reddit.
And I get that it's cool to bash Reddit on HN, but the sense that "I don't visit sites like that ... I exclusively visit HN" is really weird.
For what it's worth I have an 18 Year Club account on Reddit and I'm still active.
See this for the screen you get when it's blocking:
Perhaps when they detect abuse (screen scraping folks trying to avoid the API costs) from these shared IPs?
My memory isn't that great and I rarely look at reddit (just the occasional search results) but I think there might have been a similar block on old for a bit earlier (closer to when the block on the main domain started).