Profile details like display name and bio, are not updated from Atom feeds of remote users
When a new remote user is created on a GNU Social account, <poco:displayName> and <poco:note> clearly get parsed and saved correctly. However, if the remote user updates those tags, and then publishes a new post, GNU Social makes no effort to update its records after it receives the updated Atom feed from PubSubHubbub or as part of a Salmon payload.