Suppose that foo-1.0-1 is available in F22, F23, and rawhide.  If I build foo-1.0-2.fc22, foo-1.0-2.fc23, and foo-1.0-2.fc24, rawhide will by updated in the next compose.  If I submit updates with autokarma enabled for f22 and f23 and only foo-1.0-2.fc22 gets sufficient karma, then f22 stable will be requested and, once it's composed and mirrored out, the upgrade path to f23 will be broken until either foo-1.0-2.fc23 gets enough karma or the packager manually requests stable.  This could take an unbounded amount of time.

Please consider adding a Bodhi feature that will cause all autokarma pushes on a branch to wait until a new build (i.e. same or newer NVR) exists for rawhide and all newer branches *and* has been requested for stable in all newer branches.

In an ideal world, composes would be instantaneous or synchronized and we could make sure that there's never a state in which the old branch is composed first, but, in the mean time, simply making autokarma insist on tagging the builds in the correct order would avoid frequent long periods of time in which the upgrade path is broken.