#Wikipedia is the centre of attention, it is an improvement that other languages also exist and get attention from official WMF research.
This long-standing bias of no official attention means that "it" does not really exist because "it" is not officially studied and therefore "it" is not considered.
"It" however attracts so many people that it gets mentioned in the Guinness book of records. "It" could also be something a researcher calls "some of the most exciting things to happen in Wikimedia wikis in a long time".. "It" did not happen in a Wikimedia wiki as it is not a wiki.
What is studied is what it takes to attract new volunteers for Wikipedia. People who are willing and able to help us "share in the sum of all knowledge". That IS an aspiration. What we can achieve is "share in the sum of all available knowledge". That will not be delivered in any Wikipedia as we know it.
 "it" is not defined because it could be so many of the bright things happening in the Wikimedia ecosystem.