On Thu, May 4, 2023 at 9:36 AM Christoph Berg <myon@debian.org> wrote:
They won't go away, they will eventually be moved to apt-archive.postgresql.org and can indefinitely used there. Just not with any updates.
When that happens isn't clear yet, but with the LTS releases I usually copy packages over and remove the (then read-only) original packages from apt.postgresql.org only months later, after an announcement.