The previous commands didn't worked on MacOSX Catalina.
The install was done by default as described here https://apple.stackexchange.com/a/214075/361715 only the VPN component was checked.
sudo defaults write /Library/LaunchAgents/com.cisco.anyconnect.gui.plist RunAtLoad -bool false and sudo defaults write /Library/LaunchDaemons/com.cisco.anyconnect.vpnagentd.plist RunAtLoad -bool false as described here https://community.cisco.com/t5/vpn-and-anyconnect/anyconnect-secure-mobility-disable-the-automatic-launch-on-login/m-p/3790793/highlight/true#M148875 but the commands messed up the files content and didn't disabled the startup.
sudo plutil -replace RunAtLoad -bool NO /Library/LaunchAgents/com.cisco.anyconnect.gui.plist and sudo plutil -replace RunAtLoad -bool NO /Library/LaunchDaemons/com.cisco.anyconnect.vpnagentd.plist Those didn't messed up the files content and infact they have set the RunAtLoad to false but didn't disabled the startup.
The other test that I had on this were to delete only the /Library/LaunchAgents/com.cisco.anyconnect.gui.plist as described here https://apple.stackexchange.com/a/269517/361715 which also didn't work for me on Cisco Anyconnect v4.8.xxxxx
The startup thing is prety annoying asking for connection at startup, or for a password, or a certificate, or so...
So I have decided two sh scripts for this. One script to disable and one script to enable it at startup.
How to use it: After you download/clone this project on your Mac, open the Terminal app change the directory (cd) to point where you downloaded and extracted the files then chmod +x those files eq: cd Downloads/Disable_CiscoVPN_at_Startup_MacOSX-master chmod +x disable_ciscovpn_startup.sh chmod +x enable_ciscovpn_startup.sh
or one line chmod +x disable_ciscovpn_startup.sh && chmod +x enable_ciscovpn_startup.sh
and run ./disable_ciscovpn_startup.sh to disable the Anyconnect at startup or ./enable_ciscovpn_startup.sh to enable the Anyconnect at startup
Note: You don't need to run those files with sudo command.
If you want to contribute to this script please let me know in the Issues section if you find any errors also you may fork it, improve it and so on...
The scripts were tested only on MacOSX Catalina 10.15.3 and with Cisco Anyconnect v4.8.00175 as per february 8th, 2020 You may report back your tests also.
This code is under GPL v3 and MIT license also free to use and distribute.