In Ubuntu the GUI for upgrading packages is update-manager allowing debconf questions to be answered when needed and Ubuntu also offers unattended-upgrades for upgrading packages in the background and it keeps back packages from upgrading when configuration-file changes would need user interaction during the upgrade. Unattended-upgrades can be configured to perform upgrades during system shutdown.
Gnome Software in Bionic started offering performing upgrades during shutdown using PackageKit independently from update-manager and unattended-upgrades without offering all of the features of either one.
Unless there is a decision to fully switch to Gnome Software I suggest disabling the "Install pending software updates" on the shutdown screen to avoid confusing users.
In Ubuntu the GUI for upgrading packages is update-manager allowing debconf questions to be answered when needed and Ubuntu also offers unattended-upgrades for upgrading packages in the background and it keeps back packages from upgrading when configuration-file changes would need user interaction during the upgrade. Unattended-upgrades can be configured to perform upgrades during system shutdown.
Gnome Software in Bionic started offering performing upgrades during shutdown using PackageKit independently from update-manager and unattended-upgrades without offering all of the features of either one.
Unless there is a decision to fully switch to Gnome Software I suggest disabling the "Install pending software updates" on the shutdown screen to avoid confusing users.