I haven’t checked all their content but at least going through the latest articles all of them are either by ABC editors or paid freelancers. From what I can see they don’t do guest op-eds where they shirk any responsibility for the content.

Saying “they differentiate between analysis and opinion” is untrue because they literally don’t have material marked as “Opinion”.

It’s possible they used to do them, but no longer does.

The motivation behind [Opinion] prefix is to avoid accrediting content to publications that they don’t explicitly endorse. In this case it looks like they do.

That said, I don’t disagree that the whole approach is confusing.