Well, I know that if Fallen == NonPlayable, no bugs about them should be reported because... well, Fallen == NonPlayable. But I tought I should mention that someone didn't check that screen in Advanced properly (not trying to make anyone feel guilty, mistakes happen and this is minor).
Also, Frogboy in the changelog said that advanced was for when custom factionswhen they were possible (which I understood as "not yet but the tech for Advanced button works now").