What’s changed
After many misunderstandings and confusion, the upstream ZwaveJS2MQTT project has been renamed to Z-Wave JS UI!
Many users were confused about the 'MQTT' part, thinking it needs an MQTT Broker to work when its most important feature is to be a full-featured Control Panel UI for Z-Wave JS. The add-on is going to follow upstream and thus has applied the same naming change.
Besides upgrading, as usual, no additional action is needed.