When my /proc/cmdline includes a 3, and/or when

# systemctl get-default multi-user.target

and TDM is not running, doing an apt-get upgrade that includes a newer tdm, starts tdm, wresting the console from whatever I am doing while the upgrade is in process. I don't want that to happen. It's very disturbing. Is there a way to configure it only to restart, but never start, as a result of an apt/apt-get/aptitude installation or upgrade process?