Yes, misapprehension.
According to the Ofcom regulation checker [1] (linked to by The Register article), the Online Safety Act does not apply to this content.
Here's the most pertinent section (emphasis mine):
> Your online service will be exempt if... Users can only interact with content generated by your business/the provider of the online service. Such interactions include: comments, likes/dislikes, ratings/reviews of your content including using emojis or symbols. For example, this exemption would cover online services where the only content users can upload or share is comments on media articles you have published...
[1]: https://ofcomlive.my.salesforce-sites.com/formentry/Regulati...
> Your online service will be exempt if... Users can only interact with content generated by your business
As soon as your blog allows comments which other people can read, then you're allowing people to interact with content not generated by your business.
is this legal advice you are offering, as someone practicing law in the uk? because you are all over this thread stating your opinion very confidently.
(conveniently, there is no risk to yourself if you happen to be wrong or misinformed.)
Perhaps the author is being outwardly cautious but knowingly borderline-obtuse as a form of protest against a dumb law.