Description of problem: yumex-dnf is missing from Xfce installations and ARM disk images. Version-Release number of selected component (if applicable): Reproducible with Fedora-25-20161003.n.0.
Looks like we didn't track the name change. https://pagure.io/fedora-comps/pull-request/53
Pull merged. Should be fixed in tomorrows compose. ;)
Verified, included in Beta 1.1. Thanks Kevin!