You can't have encryption without authentication, because a man in the middle can snoop your connection.
You can have authentication without encryption. This is what PGP signed messages are.
I'll admit it's weird to call a cryptographic signature a "trusted hash", which makes it seem like the author of the post you're responding to doesn't know what they're talking about. But it's totally possible to to have trust without encryption or TLS. TLS isn't even the best protocol for signing out there, as the whole thing depends on CAs being trustworthy (which they aren't).
All that said, if you want trust on the internet, start with HTTPS. Sure, you don't need the encryption for delivering non-secret content, but it's the easiest way to set up trust and the only one non-technical people are likely to verify in any way (because their browser does it for them). It doesn't provide very strong guarantees, but it's better than nothing. If you want more go with PGP.
And the fact that you can use PGP over HTTP doesn't in any way mean that HTTP is secure in general.