That's an interesting report, but it's not really talking about Knowledge Graph *use*, which is largely internal, but rather display of KG Cards in search results -- and primarily those search results which are of interest to SEOers.  The comments are interesting to read as well, as the readers immediately pivot into how to SEO entities when pages become irrelevant.

  

In a word, no.  Google acquired Metaweb, the company that built Freebase, which forms the core of the Knowledge Graph in 2010.  Metaweb was founded in 2005 (interesting Google search: "Metaweb founding") and started extracting information from Wikipedia into Freebase in 2006. https://www.freebase.com/m/0gw0?links&lang=en&historical=true

The first DBpedia release was in 2007.  Semantic information nets go back to the 60s. TBL coined the term "semantic web" in 2006.

WikiData is a great project, but this progress has been building, excrutiatingly slowly, over decades.  One could even make the argument that WikiData is the result of Knowledge Graph and its antecedents rather than the other way around.

Tom