More critically, the proof-of-concept so far appears to lack any real work on moderation tools or implementing a web of trust system. These would be absolutely vital components for a federated encyclopedia to have any chance of controlling quality and avoiding descending into a sea of misinformation and edit wars between conflicting "truths." Centralized oversight and clear enforced guidelines are key reasons why Wikipedia has been relatively successful, despite its flaws.
Without a robust distributed moderation system in place, a federated encyclopedia runs the risk of either devolving into siloed echo chambers pushing various agendas, or becoming an uncoordinated mess making it impractical as a general reference work. The technical obstacles around federating content policies, privileges and integrated quality control across instances are immense challenges that aren't obviously addressed by this early proof-of-concept.
While novel approaches like federation are worth exploring, straying too far from Wikipedia's principles of neutral point-of-view and community-driven policies could easily undermine the entire premise. Lofty goals of disrupting Wikipedia are admirable, but successfully replacing its dominance as a general reference work seems extremely unlikely without solving these fundamental issues around distributed content governance first.