Thanks to Máirín Duffy for pointing this out - somehow I and apparently everyone else didn't notice it for five years! Since somewhere between Fedora 22 and Fedora 25 (I can't pin it down any further as I don't have any 23 or 24 images handy for some reason), our live images don't have 'rhgb' in the arguments for the boot menu entries. So when you boot them, you don't get a graphical bootsplash, you get a "wall o' text" boot process. After install, the installed system does have 'rhgb' in the args, so the graphical bootloader runs. It's just when booting the live images themselves. bcl and I think it's most likely this got lost in the transition from livecd-creator to livemedia-creator. And indeed the respin live images - https://dl.fedoraproject.org/pub/alt/live-respins/ - have working bootsplash; those are still built with livecd-creator because the person doing those respins prefers it. CCing a few relevant folks here. I think it'd probably be safe to change this now for F34 final, but if we don't want to poke it after Beta we could change it for Rawhide and have it fixed for F35 onwards.
https://github.com/weldr/lorax/pull/1131 I'm only planning on pushing this to rawhide unless someone really wants it in F34.
I'm a bit conflicted - on the one hand now we know about it it'd be kinda nice to fix it, OTOH it doesn't seem to have bothered anyone for ~10 releases so what's the harm in one more :P