Re: Postgres 15 upgrades and template1 public schema

On Wed, Oct 19, 2022 at 23:30:58 +0200,
  Thomas Kellerer <shammat@gmx.net> wrote:
>
>Bruno Wolff III schrieb am 19.10.2022 um 22:36:
>>I noticed when I did an upgrade from Postgres 14 to 15 that the
>>public schema in template1 was still owned by postgres instead of
>>pg_database_owner. I was expecting it to change because the release
>>notes said that new database clusters would have that. But shouldn't
>>new clusters use what is set in template1?
>
>This is explained in the release notes:
>
>  The change applies to new database clusters and to newly-created
>  databases in existing clusters.
>  Upgrading a cluster or restoring a database dump will preserve
>  public's existing permissions.

How do new databases in pre-existing clusters get the new public schema 
security if it doesn't come from template1?