To disable autologin on tty1:
sudo ln -sf /lib/systemd/system/getty@.service /etc/systemd/system/getty.target.wants/getty@tty1.service
To enable autologin on tty1:
sudo ln -fs /etc/systemd/system/autologin@.service /etc/systemd/system/getty.target.wants/getty@tty1.service