Jo, I believe that Walter's profile was probably originally PPPed to protect the LNAB/Last Name at Birth through the various merges that have taken place. Alternately, it may have been PPPed to prevent the removal of his parents' profiles. And often, the PPP protection was added as a temporary measure and should already have been removed. Removal, however, can only be done by a Project Leader (and WikiTree Leaders?).
Previously, members could request a profile be PPPed without having to place the profile under a project's management. As I mentioned, this was generally done as a temporary measure to protect the LNAB when merges were proposed or to prevent the removal of the parents' profiles.
Our newly updated PPP guidelines now require (?) that a PPPed profile have a Project as one of its managers and that Project's Template be added to the profile.
Many profiles that were PPPed without having a project added undoubtedly still exist in the system. As Doug suggests, we should alert their managers (if they are active), check ourselves if they might fit an existing project, or bring them to membership's attention here in G2G.