We do verify content creators on our forum, like Henry Fisher from Techlore or Yael Grauer from Consumer Reports for two examples on that list.
We don’t really have an exact criteria on when this happens, but I think it’s generally just based on a vibe-check and whether their audience is similarly sized or larger than Privacy Guides’ own audience already, which is the case in those examples.
Ultimately there is not significant harm in not verifying authors though. We verify all developers who are being discussed on the forum because people are actually using their tools already and inherently have some trust in them, and because since we recommend various software products there should be a clear conflict of interest indicator in discussions.
On the other hand, written content that is published here should generally speak for itself.
Writing articles and making videos is what we do here ourselves, and frankly we do it better than probably 90% of people out there, IMHO. If your content is independently posted by someone else — like soatok’s blogs for example — then it probably belongs in Privacy as a real on-topic discussion. If your content isn’t notable enough to be independently posted here by the community already, then it probably doesn’t meet our standards in the first place, no offense.
Ultimately, this is not really a community for self-promotion. I am more than happy to have community members who also happen to post their work and talk about it, but I am less happy with people who join the community to post their work. These are distinct things and I think a self-promotional category would only encourage the latter.
There is no rule against posting your own work to Privacy either. However, if it doesn’t add any new information to the world then it will likely be removed, and it’ll be a pretty bad look if someone is overly self-promotional. I trust our community members to use their best judgement and know the difference between posting something like a blog post that does unique and novel research into Session’s encryption, and a blog post that covers information essentially already covered on privacyguides.org in a slightly different way 
We do have a program where guests can post an article to Privacy Guides directly, and this has the benefit of being edited and approved by an editor of the site.