User blog comment:DaNASCAT/Technical Update: November 11, 2015/@comment-5558012-20151116005645/@comment-5558012-20151116181039

Worse, much worse. If I know the names of the categories, having a random category with the word I typed elsewhere in the category name appear instead offers zero help and makes adding categories even harder.

This could be helpful if the word you first type doesn't match the first word of an existing category title (ie. say only two categories match the first word at the beginning of its name, x y and x z, then look for other categories with that word, w x, a b c x, etc).