Wow! I "caught" N Gauthier (one of our Arborists) completing a random merge that I had proposed back in 2018, but that couldn't be completed because of the privacy setting(s) on one or both profiles.
I asked N what had happened to make this possible, and N replied "I have been working on very old default merge requests and when necessary (such as in this case), filing unresponsive profile manager requests to get them merged. Still have hundreds to go through..."
N Gauthier is a wonderful WIkiTreer for taking on this work to improve the WikiTree, including clearing the oldest merge proposals from my own "pending merges proposed by me" list.