I see how there's no magic bullet or really good term to express a notion of two groups of countries. But the metaphor gets really tired when Australia is part of the Global North and Taiwan or China are in the Global South.
I'm not versed enough in economy, but I'd wager Brazil and Mexico could also be controversial entries, if we had to compare them to Russia for instance.
I feel this is better addressed with terms like G20 which don't rely on any metaphor or imagery.
In the context of the article they're pretty clear about their sources and what they mean by global north and south.
For instance if we're addressing the amount of research on the autism spectrum or depression, I don't expect Russia or Australia to be significantly ahead of China or Brazil.
The same way putting Portugal and Brazil in different groups, but the UK and Australia in the same doesn't feel helpful.
There are many points in the article looking at colonization and Anglophony, these historical or cultural distinctions could be a better split perhaps IMHO. Or just embrace the complexity and not reuse any specific concept to group the countries they want to focus on.
How can a neurodiversity paradigm represent the people whose data it appropriates: colonizes?
[0] https://en.wikipedia.org/wiki/Global_North_and_Global_South
It's a global heatmap style chart of autism research.
Http://prevalence.spectrumnews.org/