Something I have been noticing recently with other theme updates and developments is the “standard” test data contains a lot of uncategorized posts. This is mostly due to WordPress requiring every post have a category assigned to it; and when the test data was being generated / written the focus was on the content and not so much on the meta data of the post.
This lead to the latest feature I have written into the theme, which is to simply not show a category reference if the only category used is the default Uncategorized. Of course if the default category is renamed then it will be used like any other assigned category.
As an example, this post will be left assigned to the default Uncategorized category.