> So I guess the distro default needs to be set in another place? It seems wrong to have no way of opting out of the hostonly setting.
Distro defaults can be overwritten using a configuration file with a name
alphabetically greater than 01-dist.conf inside /etc/dracut.conf.d
E.g.:
$ cat /etc/dracut.conf.d/99-custom.conf
hostonly="no"
hostonly_cmdline="no"