I have installed Fedora 28 offitial release. I've installed xfce and removed GNOME. Than I've set lightdm as desktop login manager. But when I've upgraded to 29 GNOME was back and the login manager was set to gdm. I've found that I could use different Fedora spins (like the xfce spin) and I'll get a preinstalled xfce desktop. But what about the next upgrade? Will I get GNOME DE again when I upgade to v30 and is therea way to switch to fedora xfce spin from offitial fedora without reinstall?
You can take a look at the file /root/anaconda-ks.cfg. This is a better explained answer: