Create a server that can only connect to the internet via tor, set up some iptables rules to ensure you don't run into issues, create the site with a HSV3 address since those have a ton of benefits as compared to the old addressing scheme. Depending on what you're hosting you may want to disable the extra couple hops on the server side to reduce latency but that'll make your server easy to find.
Onion services are great for private ssh over the internet, or hosting your own sort of wiki. I haven't tried configuring a VPN onion, not sure if there's any real benefit considering the crazy latency you'd experience and the fact that it's a non-standard setup.
As for, >>939602 i'm guessing they're suggesting to look at how tails handles it's connection to the network rather than how it handles hosting since tails hasn't released an OS for hosting yet (but it is planned)