“The following upgrades have been deferred due to phasing” is the new “The following packages have been kept back”

In the latest Ubuntu 24.04 LTS also known as Ubuntu Noble, the developers have decided to change warning messages that are shown on APT update.

APT Update with Warning Message

It is certainly confusing to see message saying “The following upgrades have been deferred due to phasing”. Once you Google it, you will just find out that it means what error message “The following packages have been kept back” meant.

Solution?

You can usually force install these packages using:

sudo apt install [... package names ...]

If there are further errors shown then do not install but wait. But usually it is safe to install these manually.