Their problem is that they mix up the two terms "non-certified" and "private" even though a private channel has to be certified before being published, or at least it used to be the case.
In other words, Roku checks the channel Code as in software, for errors or currently-unsupported features, and will kick it back as certified or not. I often upload my public channel packages as private to test them before going public, but it's the same package.
Roku should state clearly that "private" channels are shutting down if that's what they mean instead of confusing people.
But then I haven't read their actual article. Do you have a link?