Isn't the purpose of a PM to keep tabs on what is going on in a profile? What is the purpose of a PM who is long gone? I ran into issues with an unresponsive PM when I first joined Wikitree. He had uploaded thousands of profiles in a gedcom in 2011, locked them, and then, for whatever reason, disappeared. I kept trying to contact him, but there was no response. I finally figured out the magic formula outlined by Anne B, and after lots more waiting he was removed as PM. The wait served no purpose. It was obvious that he had been inactive for years. The basic information for the profiles of my family members was just wrong. It didn't have anything to do with a merge. I was very frustrated with the whole stupid process which took me about 6 months to get fixed
If there is no reason for something, like keeping an unresponsive manager on, then why do it? It makes a mess, like others keep saying. And we can solve the issue of "legacy" by "acknowledging " the ancient upload that made the mess in the first place.