Re: the realities of Power BI today
The story only discussed exposing corporate databases/source to Power BI environment. It did not discuss the blending of on-premises Microsoft BI systems/assets with Power BI in the cloud. The price difference between the Excel-inclusive ProPlus version of PowerBI and the non-Excel-inclusive (Standalone) versions of Power BI is $168, not $500. Finally, I'd point out that Cindi Howson, an analyst, was quoted withing this article as critical of the overlaps among the various interfaces. She also pointed out the lack of an enterprise data model.
Otherwise, you have lots of good questions here, though many are about the status of on-premises products from Microsoft, which this story did not cover. I'm going to ask Microsoft to respond to the specifics on Power BI capabilities on Power Pivot and Power View that you point out -- and perhaps they'll have more to say about your other comments.