Credit for this discovery goes to my cousin and co-host, Donya Williams. This latest addition to Ancestry's DNA tools was so subtle that I missed it. At the time of writing this article, this little tool remains unnamed. In the interest of referring to it by a specific name, I refer to it as the Ancestry DNA Match Add Tool (DMA Tool, for short).
This episode is also available as a blog post: https://genealogyadventures.net/2020/07/01/ancestrys-dna-match-add-tool/