You can always enable it again by creating /boot/avahi if needed.
Sticky Fingers runs a service called “avahiswitch”, that checks for the file /boot/avahi and, if present, enables and starts the avahi-daemon and then deletes /boot/avahi. This comes in handy for the initial, headless setup of your Kali-Pi if you connect to it via ethernet gadget or network cable using dhcp.
If you don’t need the “avahiswitch” service, just disable it via:
systemctl disable avahiswitch
The source code for the service can be found here: