AFAICT, "openSUSE Leap 15.1" and "openSUSE Leap 15.2" can now be selected in the "OS" rolldown widget (the unlabeled one next to "Hardware"). I don't see "openSUSE Leap 15.0" there, but that shouldn't be a problem since 15.0 has already reached EOL, so any "dutiful" bug reporters should have gone over to some more recent OS version.