Below is an example of the silent install options we use in many of our computer labs. Since you are using Named User licensing, you can point to your organization's ArcGIS Online instance, rather than the generic www.arcgis.com, to potentially save users steps logging in. This is especially handy if you have configured your instance to use Enterprise Logins for users, and configured Enterprise logins as your only login option. Then your users are sent straight to your single-sign-on dialog when they start-up Pro, rather than having to fill out Esri's generic login dialog and find their way to your organization.
msiexec.exe /i <path to installer>\ArcGISPro.msi \
ALLUSERS=1 \
SOFTWARE_CLASS=Professional \
AUTHORIZATION_TYPE=NAMED_USER \
CHECKFORUPDATESATSTARTUP=0 \
LOCK_AUTH_SETTINGS=TRUE
One important note: make sure you specify the parameters in the order presented above!
(The installer for ArcGIS for 2.4.2, and maybe any 2.4.x, introduced a bug whereby it does not properly parse the command line arguments, so re-arranging them can cause unexpected failures. For example, if you construct your command line in the order in which the parameters are explained in the documentation, then the installer will report success, however, the settings you specified will not be applied correctly, and you will get errors or unexpected behaviors when you try to login to Pro.)