That is a good point, apt-key is deprecated.

However it is only a warning. i.e. Don’t continue to use this its going away, there is a newer way of doing it now. I’m sure it will be addressed when the docs are updated.

The point I am making is that until the documentation/manual is updated the only change required to install on Ubuntu 22.04 is changing focal to jammy. There is no additional steps, a very small deviation from what is already documented.

If you trace back the release notes and related jiras there is outstanding items relating to updating the documentation.