I don't think you will find any relevant doco specific to it, as it is basically standard Dynamics 365/Dataverse behvior. In the Standard implementation all of the Web Pages, Lists, Basic Forms, Multi step forms etc definitions are standard Dataverse records and so are visible and editable by anyone with appropriate Security Role permissions. As such you will see that the Owner of those records could be different system users, and if they leave the record is still visible and editable but could if desired be re-assigned by anyone with appropriate Security Role Privileges (and off the user record you could do a bulk reassign).
There is none of the Connection owner visibility issues etc as everything runs as the SYSTEM account and you don't access it.
Where you can get minor issues is if you are creating Dataverse Workflows (or register a plugin step to run as a specific user) and the owner of the Workflow has their licence pulled etc and it is running as the owner the workflow will then fail as the owner is not licenced - the way around this is to either run them as the user invoking them or create a non-interactive account (basically a service account that after being setup does not need to consume a licence) and assign it as the owner of the workflows - this again is standard Dynamics 365/Dataverse and not specific to Power Pages.
