After a MacBook restart there are usually a few applications that will autostart/launch and depending on what you normally do it might be good or might just be annoying.
I try to keep the number of auto started applications to a minimum and the most recent application i disabled autostart for was Cisco AnyConnect Secure Mobility Client.
I’m currently running macOS Catalina version 10.15.6 and auto start of Cisco AnyConnect Secure Mobility Client seems to be controlled by the com.cisco.anyconnect.gui.plist file only. Pre Catalina both com.cisco.anyconnect.gui.plist and com.cisco.anyconnect.vpnagent.plist was involved.
The simple solution and being able to go back if something goes south is to rename the com.cisco.anyconnect.gui.plis file which is located in the directory /Library/LaunchAgents
File permission is 644 meaning you have to use sudo to rename the file or if you prefer you can always use su command to become user root and then rename the file.
I just ran the below command and then rebooted my MacBook and Cisco AnyConnect Secure Mobility Client doesn’t auto start anymore:)
sudo mv /Library/LaunchAgents/com.cisco.anyconnect.gui.plist /Library/LaunchAgents/com.cisco.anyconnect.gui.plist.20200922.org