The driver iwlwifi may break dappnode host, making wifi service to stop working. Driver iwlwifi is crutial for the host (with intel hardware) to detect the network interface, if iwlwifi not present the network interface may not be recognized by the host.
Is not a dappnode issue but a driver/debian issue
Consider open an issue at https://bugs.debian.org/cgi-bin/pkgreport.cgi?pkg=firmware-iwlwifi;dist=unstable and look for better support