Thanks a lot @FranciscoD that worked. As per the BugZilla workaround instructions. It must be the the same bug.
sudo dnf downgrade -y iwl7260-firmware
sudo rmmod iwlmvm iwlwifi
sudo modprobe iwlwifi
To confirm, upgrading from iwl7260-firmware-1:25.30.13.0-94.fc30.noarch to iwl7260-firmware-1:25.30.13.0-99.fc30.noarch stops the Intel 9560NGW wifi module working. (And downgrading back to iwl7260-firmware-1:25.30.13.0-94.fc30.noarch fixes it.)