The article (blog post) links to an earlier blog post by the same author which contains previous discussion and plenty of examples of the singular they: <a href="https:&#x2F;&#x2F;illinois.edu&#x2F;blog&#x2F;view&#x2F;25&#x2F;247504" rel="nofollow">https:&#x2F;&#x2F;illinois.edu&#x2F;blog&#x2F;view&#x2F;25&#x2F;247504</a>