For gnome (maybe other window managers?) to launch apps minimized (using Teams as an example in the comments)

launchmin.sh

#! /bin/bash

# usage: launchmin.sh /usr/bin/teams "Chat | Microsoft Teams"
# 
# $1 is the path to an executable that runs in a window
# $2 is a quoted string to uniquely identify that window
#
# prerequisites: the xdotool and wmctrl packages need to be installed
# 
# I wrote this to launch Microsoft Teams for Linux on startup but in a minimized 
# window but it should work for any app if you can figure out a reliable pattern
# for matching its window title. Astonishingly, there is nothing built into the 
# gnome tweaks or into the .desktop file specification that allows you to set 
# minimize-on-start generically-- each app is responsible for providing its own
# command-line flags for doing so, if the author so chooses. So this will hack
# around this with xdotool and wmctrl.
# 
# Note for Microsoft Teams, documented here in case needed later for other apps:
# If you add Exec=launchmin.sh /usr/bin/teams "Chat | Microsoft Teams"
# to a teams.desktop file, e.g. the one in $HOME/.config/autostart, the teams app 
# will overwrite it with a vanilla version of its desktop file. To prevent that,
# make your changes to a copy of that file in the same directory. In the original 
# teams.desktop file set X-GNOME-Autostart-enabled=false and make the file 
# write-only. Now you will only have one instance of teams launching on startup,
# minimized. The other one will be ignored and Teams will not be able to 
# overwrite it.
#
# Again, this script is not just for Microsoft Teams, the above is just a helpful
# note for those who happen to be using that app.

$1 && unset mywinid && while [ -z $mywinid ];do mywinid=$( wmctrl -l|grep "$2"|cut -d' ' -f1 ); sleep 1; done && xdotool windowminimize $mywinid