To my knowledge, the project isn't dead...but, it has been moving at a horribly slow pace for a very long time.
Funkwhale is a pretty cool project, but it's one of those things where the ActivityPub implementation really was bolted on well after the core experience was defined and developed. It was meant to be a Grooveshark clone, while a lot of people were hoping to use it in a more social way, like SoundCloud.