Regarding submission of Paclets to the Wolfram Language Paclet Repository, a contributor is encouraged to provide a PublisherID to offset trust issues ensuing from its non-curated status.
Although a personal or organizational PublisherID is self-explanatory, what about if I’m wanting to resurrect a package authored by some 3rd party who made it public some time ago? I don’t want to claim authorship (a field in the Paclet submittal form), yet don’t want to impose hassle on that 3rd party, whom might not want to be contacted or may be long-departed (hence the “Estate of…”).
We do not have a full answer to your question but some points have emerged. One is that Publisher ID and authorship are not the same thing. Another (which it is clear you agree with) is that we really do not want the ID to be directly from someone unable to give approval for use. To make this more clear, we think it is acceptable to name that person in the ID, e.g. PublicDomainWorkOfOriginalAuthorName/pacletname,
but not acceptable to just do
OriginalAuthorName/pacletname.
As for authorship, in the Wolfram Function Repository we tend to use either of the below styles: Contributor (original work by <original author's name>)
or
Original author (additional contributions by <submitter's name>).