Has any Cessna Denali ever flown yet...?
According to Flying Magazine's September 2018 profile of the Denali:


  The Denali’s first flight is expected early next year, with an entry
  into service during the first half of 2020.


As for the performance figures you mentioned, the same article says:


  The Denali will weigh less than 12,500 pounds to prevent the need for
  a type rating, but at the moment, Cessna hasn’t released a gross
  weight number, nor any performance figures. Those won’t be made public
  until after the Denali’s first flight next year.