That's a very unfortunate situation. The API change is a clear breakage of the Update
guidelines. The version bump that is done in the patch 0.28.1 → 0.29.0 is also wrong,
since this number also describes the python API, and changes that remove names need to
bump the major number to signal backwards incompatibility.
The least-bad solution would be to add back something in the python API to restore
compatibility. Some feedback from the dnf side whether this is possible would be very
useful.